Allow control of individual columns to be (un)writable.

Most protocols just want to limit COL_INFO or COL_PROTOCOL
so give that level of granularity.

Bug: 12144
Bug: 5117
Bug: 11144
Change-Id: I8de9b7d2c69e90d3fbfc0a52c2bd78c3de58e2f8
Reviewed-on: https://code.wireshark.org/review/15894
Reviewed-by: Jeff Morriss <jeff.morriss.ws@gmail.com>
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

39 files changed, 167 insertions, 157 deletions

diff --git a/epan/column-info.h b/epan/column-info.h
index cca684e83a..4fe638ca06 100644
--- a/epan/column-info.h
+++ b/epan/column-info.h
@@ -56,6 +56,7 @@ typedef struct {
   const gchar        *col_data;             /**< Column data */
   gchar              *col_buf;              /**< Buffer into which to copy data for column */
   int                 col_fence;            /**< Stuff in column buffer before this index is immutable */
+  gboolean            writable;             /**< writable or not */
 } col_item_t;
 
 /** Column info */
diff --git a/epan/column-utils.c b/epan/column-utils.c
index 846c177c6b..bbff48a21e 100644
--- a/epan/column-utils.c
+++ b/epan/column-utils.c
@@ -138,6 +138,7 @@ col_init(column_info *cinfo, const struct epan_session *epan)
     col_item->col_buf[0] = '\0';
     col_item->col_data = col_item->col_buf;
     col_item->col_fence = 0;
+    col_item->writable = TRUE;
     cinfo->col_expr.col_expr[i] = "";
     cinfo->col_expr.col_expr_val[i][0] = '\0';
   }
@@ -145,25 +146,55 @@ col_init(column_info *cinfo, const struct epan_session *epan)
   cinfo->epan = epan;
 }
 
-#define COL_GET_WRITABLE(cinfo) (cinfo ? cinfo->writable : FALSE)
-
 gboolean
-col_get_writable(column_info *cinfo)
+col_get_writable(column_info *cinfo, const gint col)
 {
-  return COL_GET_WRITABLE(cinfo);
+  int i;
+  col_item_t* col_item;
+
+  if (cinfo == NULL)
+    return FALSE;
+
+  /* "global" (not) writeability will always override
+     an individual column */
+  if ((col == -1) || (cinfo->writable == FALSE))
+    return cinfo->writable;
+
+  if (cinfo->col_first[col] >= 0) {
+    for (i = cinfo->col_first[col]; i <= cinfo->col_last[col]; i++) {
+      col_item = &cinfo->columns[i];
+      if (col_item->fmt_matx[col]) {
+        return col_item->writable;
+      }
+    }
+  }
+  return FALSE;
 }
 
 void
-col_set_writable(column_info *cinfo, const gboolean writable)
+col_set_writable(column_info *cinfo, const gint col, const gboolean writable)
 {
-  if (cinfo)
-    cinfo->writable = writable;
+  int i;
+  col_item_t* col_item;
+
+  if (cinfo) {
+    if (col == -1) {
+      cinfo->writable = writable;
+    } else if (cinfo->col_first[col] >= 0) {
+      for (i = cinfo->col_first[col]; i <= cinfo->col_last[col]; i++) {
+        col_item = &cinfo->columns[i];
+        if (col_item->fmt_matx[col]) {
+          col_item->writable = writable;
+        }
+      }
+    }
+  }
 }
 
 /* Checks to see if a particular packet information element is needed for the packet list */
 #define CHECK_COL(cinfo, el) \
     /* We are constructing columns, and they're writable */ \
-    (COL_GET_WRITABLE(cinfo) && \
+    (col_get_writable(cinfo, el) && \
       /* There is at least one column in that format */ \
     ((cinfo)->col_first[el] >= 0))
 
diff --git a/epan/column-utils.h b/epan/column-utils.h
index c51397a008..2da28d78ad 100644
--- a/epan/column-utils.h
+++ b/epan/column-utils.h
@@ -149,16 +149,18 @@ WS_DLL_PUBLIC void	col_fill_in_error(column_info *cinfo, frame_data *fdata, cons
 /** Are the columns writable?
  *
  * @param cinfo the current packet row
+ * @param col the writable column, -1 for checking the state of all columns
  * @return TRUE if it's writable, FALSE if not
  */
-WS_DLL_PUBLIC gboolean	col_get_writable(column_info *cinfo);
+WS_DLL_PUBLIC gboolean	col_get_writable(column_info *cinfo, const gint col);
 
 /** Set the columns writable.
  *
  * @param cinfo the current packet row
+ * @param col the column to set, -1 for all
  * @param writable TRUE if it's writable, FALSE if not
  */
-WS_DLL_PUBLIC void	col_set_writable(column_info *cinfo, const gboolean writable);
+WS_DLL_PUBLIC void	col_set_writable(column_info *cinfo, const gint col, const gboolean writable);
 
 /** Sets a fence for the current column content,
  * so this content won't be affected by further col_... function calls.
diff --git a/epan/dissectors/asn1/lte-rrc/packet-lte-rrc-template.c b/epan/dissectors/asn1/lte-rrc/packet-lte-rrc-template.c
index 0a57bc4a86..7917f64599 100644
--- a/epan/dissectors/asn1/lte-rrc/packet-lte-rrc-template.c
+++ b/epan/dissectors/asn1/lte-rrc/packet-lte-rrc-template.c
@@ -3007,13 +3007,13 @@ dissect_lte_rrc_Handover_Preparation_Info(tvbuff_t *tvb, packet_info *pinfo, pro
   /* Don't want elements inside message updating Info column, so set now and
      freeze during dissection of PDU */
   col_set_str(pinfo->cinfo, COL_INFO, "HandoverPreparationInformation");
-  col_set_writable(pinfo->cinfo, FALSE);
+  col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
 
   ti = proto_tree_add_item(tree, proto_lte_rrc, tvb, 0, -1, ENC_NA);
   lte_rrc_tree = proto_item_add_subtree(ti, ett_lte_rrc);
   dissect_lte_rrc_HandoverPreparationInformation_PDU(tvb, pinfo, lte_rrc_tree, NULL);
 
-  col_set_writable(pinfo->cinfo, TRUE);
+  col_set_writable(pinfo->cinfo, COL_INFO, TRUE);
   return tvb_captured_length(tvb);
 }
 
diff --git a/epan/dissectors/asn1/s1ap/s1ap.cnf b/epan/dissectors/asn1/s1ap/s1ap.cnf
index 18cca77d30..777c6712bd 100644
--- a/epan/dissectors/asn1/s1ap/s1ap.cnf
+++ b/epan/dissectors/asn1/s1ap/s1ap.cnf
@@ -333,7 +333,7 @@ tvbuff_t *parameter_tvb=NULL;
 
 	if (g_s1ap_dissect_container) {
 		/* Don't want elements inside container to write to info column */
-		col_set_writable(actx->pinfo->cinfo, FALSE);
+		col_set_writable(actx->pinfo->cinfo, COL_INFO, FALSE);
 		subtree = proto_item_add_subtree(actx->created_item, ett_s1ap_ToTargetTransparentContainer);
 
     	switch(handover_type_value){
@@ -378,7 +378,7 @@ tvbuff_t *parameter_tvb=NULL;
 			break;
 		}
 		/* Enable writing of the column again */
-		col_set_writable(actx->pinfo->cinfo, TRUE);
+		col_set_writable(actx->pinfo->cinfo, COL_INFO, TRUE);
 	}
 #.FN_BODY Target-ToSource-TransparentContainer VAL_PTR = &parameter_tvb
 # I think the message is "directly encoded" into the octet string(no "double encoding")
diff --git a/epan/dissectors/packet-artnet.c b/epan/dissectors/packet-artnet.c
index 381aff1e9e..2723a111a8 100644
--- a/epan/dissectors/packet-artnet.c
+++ b/epan/dissectors/packet-artnet.c
@@ -2317,15 +2317,14 @@ dissect_artnet_output(tvbuff_t *tvb, guint offset, proto_tree *tree, packet_info
 
   size = tvb_reported_length_remaining(tvb, offset);
 
-  save_info = col_get_writable(pinfo->cinfo);
-  col_set_writable(pinfo->cinfo, FALSE);
+  save_info = col_get_writable(pinfo->cinfo, COL_INFO);
+  col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
 
   next_tvb = tvb_new_subset_length(tvb, offset, length);
 
-  /* XXX: Assumption: OK to call dmx-chan dissector under 'if (tree)' */
   call_dissector(dmx_chan_handle, next_tvb, pinfo, base_tree);
 
-  col_set_writable(pinfo->cinfo, save_info);
+  col_set_writable(pinfo->cinfo, COL_INFO, save_info);
 
   return offset + size;
 }
@@ -2813,15 +2812,14 @@ dissect_artnet_rdm(tvbuff_t *tvb, guint offset, proto_tree *tree,  packet_info *
 
   size = tvb_reported_length_remaining(tvb, offset);
 
-  save_info = col_get_writable(pinfo->cinfo);
-  col_set_writable(pinfo->cinfo, FALSE);
+  save_info = col_get_writable(pinfo->cinfo, COL_INFO);
+  col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
 
   next_tvb = tvb_new_subset_remaining(tvb, offset);
 
-  /* XXX: Assumption: OK to call rdm dissector under 'if (tree)' */
   call_dissector(rdm_handle, next_tvb, pinfo, base_tree);
 
-  col_set_writable(pinfo->cinfo, save_info);
+  col_set_writable(pinfo->cinfo, COL_INFO, save_info);
 
   return offset + size;
 }
@@ -3322,7 +3320,6 @@ dissect_artnet(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _
       break;
 
     case ARTNET_OP_OUTPUT:
-      if (tree) {
         hi = proto_tree_add_item(artnet_tree,
                                  hf_artnet_output,
                                  tvb,
@@ -3336,7 +3333,6 @@ dissect_artnet(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _
         size -= offset;
         proto_item_set_len(si, size );
         offset += size;
-      }
       break;
 
 
@@ -3435,7 +3431,6 @@ dissect_artnet(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _
       break;
 
     case ARTNET_OP_RDM:
-      if (tree) {
         hi = proto_tree_add_item(artnet_tree,
                                  hf_artnet_rdm,
                                  tvb,
@@ -3448,7 +3443,6 @@ dissect_artnet(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _
 
         proto_item_set_len( si, size );
         offset += size;
-      }
       break;
 
     case ARTNET_OP_RDM_SUB:
diff --git a/epan/dissectors/packet-bacapp.c b/epan/dissectors/packet-bacapp.c
index 33517c7894..e483496dd9 100644
--- a/epan/dissectors/packet-bacapp.c
+++ b/epan/dissectors/packet-bacapp.c
@@ -5991,8 +5991,7 @@ fObjectIdentifier(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint off
             Vendor_Proprietary_Fmt),
         object_id_instance(object_id));
 
-    if (col_get_writable(pinfo->cinfo))
-        col_append_fstr(pinfo->cinfo, COL_INFO, "%s,%u ",
+     col_append_fstr(pinfo->cinfo, COL_INFO, "%s,%u ",
             val_to_split_str(object_type,
                 128,
                 BACnetObjectType,
@@ -6255,8 +6254,7 @@ fPropertyIdentifier(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint o
                 BACnetPropertyIdentifier,
                 ASHRAE_Reserved_Fmt,
                 Vendor_Proprietary_Fmt), propertyIdentifier);
-        if (col_get_writable(pinfo->cinfo))
-            col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
+        col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
                 val_to_split_str(propertyIdentifier, 512,
                     BACnetPropertyIdentifier,
                     ASHRAE_Reserved_Fmt,
@@ -7390,8 +7388,7 @@ fConfirmedPrivateTransferRequest(tvbuff_t *tvb, packet_info *pinfo, proto_tree *
 
     len = fTagHeader(tvb, pinfo, offset, &tag_no, &tag_info, &lvt);
     fUnsigned32(tvb, offset+len, lvt, &vendor_identifier);
-    if (col_get_writable(pinfo->cinfo))
-        col_append_fstr(pinfo->cinfo, COL_INFO, "V=%u ", vendor_identifier);
+    col_append_fstr(pinfo->cinfo, COL_INFO, "V=%u ", vendor_identifier);
     offset = fVendorIdentifier(tvb, pinfo, subtree, offset);
 
     next_tvb = tvb_new_subset_remaining(tvb, offset);
@@ -7422,8 +7419,7 @@ fConfirmedPrivateTransferRequest(tvbuff_t *tvb, packet_info *pinfo, proto_tree *
             /* vendorID is now parsed above */
         case 1: /* serviceNumber */
             fUnsigned32(tvb, offset+len, lvt, &service_number);
-            if (col_get_writable(pinfo->cinfo))
-                col_append_fstr(pinfo->cinfo, COL_INFO, "SN=%u ",   service_number);
+            col_append_fstr(pinfo->cinfo, COL_INFO, "SN=%u ",   service_number);
             offset = fUnsignedTag(tvb, pinfo, subtree, offset, "service Number: ");
             break;
         case 2: /*serviceParameters */
@@ -9124,7 +9120,7 @@ fLOPR(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint offset)
     guint8  tag_no, tag_info;
     guint32 lvt;
 
-    col_set_writable(pinfo->cinfo, FALSE); /* don't set all infos into INFO column */
+    col_set_writable(pinfo->cinfo, COL_INFO, FALSE); /* don't set all infos into INFO column */
     while (tvb_reported_length_remaining(tvb, offset) > 0) {  /* exit loop if nothing happens inside */
         lastoffset = offset;
         fTagHeader(tvb, pinfo, offset, &tag_no, &tag_info, &lvt);
@@ -9172,7 +9168,7 @@ fAddListElementRequest(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guin
     guint32     lvt;
     proto_tree *subtree    = tree;
 
-    col_set_writable(pinfo->cinfo, FALSE); /* don't set all infos into INFO column */
+    col_set_writable(pinfo->cinfo, COL_INFO, FALSE); /* don't set all infos into INFO column */
 
     while (tvb_reported_length_remaining(tvb, offset) > 0) {  /* exit loop if nothing happens inside */
         lastoffset = offset;
@@ -9503,7 +9499,7 @@ fWritePropertyMultipleRequest(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tre
     if (offset >= tvb_reported_length(tvb))
         return offset;
 
-    col_set_writable(pinfo->cinfo, FALSE); /* don't set all infos into INFO column */
+    col_set_writable(pinfo->cinfo, COL_INFO, FALSE); /* don't set all infos into INFO column */
     return fWriteAccessSpecification(tvb, pinfo, tree, offset);
 }
 
@@ -9543,7 +9539,7 @@ fPropertyReference(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint of
 static guint
 fBACnetPropertyReference(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint offset, guint8 list)
 {
-    col_set_writable(pinfo->cinfo, FALSE); /* don't set all infos into INFO column */
+    col_set_writable(pinfo->cinfo, COL_INFO, FALSE); /* don't set all infos into INFO column */
     return fPropertyReference(tvb, pinfo, tree, offset, 0, list);
 }
 
@@ -9561,7 +9557,7 @@ fBACnetObjectPropertyReference(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tr
             break;
         case 1: /* PropertyIdentifier and propertyArrayIndex */
             offset = fPropertyReference(tvb, pinfo, tree, offset, 1, 0);
-            col_set_writable(pinfo->cinfo, FALSE); /* don't set all infos into INFO column */
+            col_set_writable(pinfo->cinfo, COL_INFO, FALSE); /* don't set all infos into INFO column */
         default:
             lastoffset = offset; /* Set loop end condition */
             break;
@@ -10034,7 +10030,7 @@ fReadRangeAck(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint offset)
     /* itemData */
     fTagHeader(tvb, pinfo, offset, &tag_no, &tag_info, &lvt);
     if (tag_is_opening(tag_info)) {
-        col_set_writable(pinfo->cinfo, FALSE); /* don't set all infos into INFO column */
+        col_set_writable(pinfo->cinfo, COL_INFO, FALSE); /* don't set all infos into INFO column */
         subtree = proto_tree_add_subtree(subtree, tvb, offset, 1, ett_bacapp_value, NULL, "itemData");
         offset += fTagHeaderTree(tvb, pinfo, subtree, offset, &tag_no, &tag_info, &lvt);
         offset  = fAbstractSyntaxNType(tvb, pinfo, subtree, offset);
@@ -10135,14 +10131,14 @@ fAtomicReadFileAck(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint of
 static guint
 fReadPropertyMultipleRequest(tvbuff_t *tvb, packet_info *pinfo, proto_tree *subtree, guint offset)
 {
-    col_set_writable(pinfo->cinfo, FALSE); /* don't set all infos into INFO column */
+    col_set_writable(pinfo->cinfo, COL_INFO, FALSE); /* don't set all infos into INFO column */
     return fReadAccessSpecification(tvb, pinfo, subtree, offset);
 }
 
 static guint
 fReadPropertyMultipleAck(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint offset)
 {
-    col_set_writable(pinfo->cinfo, FALSE); /* don't set all infos into INFO column */
+    col_set_writable(pinfo->cinfo, COL_INFO, FALSE); /* don't set all infos into INFO column */
     return fReadAccessResult(tvb, pinfo, tree, offset);
 }
 
@@ -10352,7 +10348,7 @@ fWhoIsRequest(tvbuff_t *tvb, packet_info* pinfo, proto_tree *tree, guint offset)
         switch (tag_no) {
         case 0:
             /* DeviceInstanceRangeLowLimit Optional */
-            if (col_get_writable(pinfo->cinfo) && fUnsigned32(tvb, offset+tag_len, lvt, &val))
+            if (fUnsigned32(tvb, offset+tag_len, lvt, &val))
                 col_append_fstr(pinfo->cinfo, COL_INFO, "%d ", val);
             offset = fDevice_Instance(tvb, pinfo, tree, offset,
                 hf_Device_Instance_Range_Low_Limit);
@@ -10360,7 +10356,7 @@ fWhoIsRequest(tvbuff_t *tvb, packet_info* pinfo, proto_tree *tree, guint offset)
         case 1:
             /* DeviceInstanceRangeHighLimit Optional but
                 required if DeviceInstanceRangeLowLimit is there */
-            if (col_get_writable(pinfo->cinfo) && fUnsigned32(tvb, offset+tag_len, lvt, &val))
+            if (fUnsigned32(tvb, offset+tag_len, lvt, &val))
                 col_append_fstr(pinfo->cinfo, COL_INFO, "%d ", val);
             offset = fDevice_Instance(tvb, pinfo, tree, offset,
                 hf_Device_Instance_Range_High_Limit);
@@ -10590,14 +10586,12 @@ fConfirmedPrivateTransferError(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tr
             break;
         case 1: /* vendorID */
             fUnsigned32(tvb, offset+tag_len, lvt, &vendor_identifier);
-            if (col_get_writable(pinfo->cinfo))
-                col_append_fstr(pinfo->cinfo, COL_INFO, "V=%u ",    vendor_identifier);
+            col_append_fstr(pinfo->cinfo, COL_INFO, "V=%u ",    vendor_identifier);
             offset = fVendorIdentifier(tvb, pinfo, subtree, offset);
             break;
         case 2: /* serviceNumber */
             fUnsigned32(tvb, offset+tag_len, lvt, &service_number);
-            if (col_get_writable(pinfo->cinfo))
-                col_append_fstr(pinfo->cinfo, COL_INFO, "SN=%u ",   service_number);
+            col_append_fstr(pinfo->cinfo, COL_INFO, "SN=%u ",   service_number);
             offset = fUnsignedTag(tvb, pinfo, subtree, offset, "service Number: ");
             break;
         case 3: /* errorParameters */
@@ -10680,7 +10674,7 @@ fWritePropertyMultipleError(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
     guint8  tag_no     = 0, tag_info = 0;
     guint32 lvt        = 0;
 
-    col_set_writable(pinfo->cinfo, FALSE); /* don't set all infos into INFO column */
+    col_set_writable(pinfo->cinfo, COL_INFO, FALSE); /* don't set all infos into INFO column */
     while (tvb_reported_length_remaining(tvb, offset) > 0) {  /* exit loop if nothing happens inside */
         lastoffset = offset;
         switch (fTagNo(tvb, offset)) {
diff --git a/epan/dissectors/packet-diameter.c b/epan/dissectors/packet-diameter.c
index 45ff749036..7bfa12c15e 100644
--- a/epan/dissectors/packet-diameter.c
+++ b/epan/dissectors/packet-diameter.c
@@ -447,12 +447,12 @@ dissect_diameter_eap_payload(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
 	gboolean save_writable;
 
 	/* Ensure the packet is displayed as Diameter, not EAP */
-	save_writable = col_get_writable(pinfo->cinfo);
-	col_set_writable(pinfo->cinfo, FALSE);
+	save_writable = col_get_writable(pinfo->cinfo, COL_PROTOCOL);
+	col_set_writable(pinfo->cinfo, COL_PROTOCOL, FALSE);
 
 	call_dissector(eap_handle, tvb, pinfo, tree);
 
-	col_set_writable(pinfo->cinfo, save_writable);
+	col_set_writable(pinfo->cinfo, COL_PROTOCOL, save_writable);
 	return tvb_reported_length(tvb);
 }
 
@@ -877,7 +877,8 @@ proto_avp(diam_ctx_t *c, diam_avp_t *a, tvbuff_t *tvb, diam_sub_dis_t *diam_sub_
 {
 	proto_avp_t *t = (proto_avp_t *)a->type_data;
 
-	col_set_writable(c->pinfo->cinfo, FALSE);
+	col_set_writable(c->pinfo->cinfo, COL_PROTOCOL, FALSE);
+	col_set_writable(c->pinfo->cinfo, COL_INFO, FALSE);
 
 	if (!t->handle) {
 		t->handle = find_dissector(t->name);
diff --git a/epan/dissectors/packet-enip.c b/epan/dissectors/packet-enip.c
index 4efe8c24e4..dce48f2275 100644
--- a/epan/dissectors/packet-enip.c
+++ b/epan/dissectors/packet-enip.c
@@ -1513,13 +1513,13 @@ dissect_tcpip_last_conflict(packet_info *pinfo, proto_tree *tree, proto_item *it
    else
    {
       /* Dissect ARP PDU, but don't have it change column info */
-      save_info = col_get_writable(pinfo->cinfo);
-      col_set_writable(pinfo->cinfo, FALSE);
+      save_info = col_get_writable(pinfo->cinfo, -1);
+      col_set_writable(pinfo->cinfo, -1, FALSE);
 
       next_tvb = tvb_new_subset_length(tvb, offset+7, 28);
       call_dissector(arp_handle, next_tvb, pinfo, tree);
 
-      col_set_writable(pinfo->cinfo, save_info);
+      col_set_writable(pinfo->cinfo, -1, save_info);
    }
 
    return 35;
diff --git a/epan/dissectors/packet-etch.c b/epan/dissectors/packet-etch.c
index 80714d6dcb..76c380b83c 100644
--- a/epan/dissectors/packet-etch.c
+++ b/epan/dissectors/packet-etch.c
@@ -729,7 +729,6 @@ dissect_etch_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void*
     }
     gbl_old_frame_num = pinfo->num;
 
-    col_set_writable(pinfo->cinfo, TRUE);
     col_append_fstr(pinfo->cinfo, COL_INFO, "%s ", wmem_strbuf_get_str(colInfo));
   }
 
@@ -785,7 +784,6 @@ dissect_etch(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
                    dissect_etch_message, data);
 
   if (gbl_pdu_counter > 0) {
-    col_set_writable(pinfo->cinfo, TRUE);
     col_prepend_fstr(pinfo->cinfo, COL_INFO, "[%d] ", gbl_pdu_counter + 1);
   }
 
diff --git a/epan/dissectors/packet-gsm_a_gm.c b/epan/dissectors/packet-gsm_a_gm.c
index efeb71102d..c093fa0113 100644
--- a/epan/dissectors/packet-gsm_a_gm.c
+++ b/epan/dissectors/packet-gsm_a_gm.c
@@ -4313,9 +4313,9 @@ de_sm_pco(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo, guint32 offset, g
 							 * dissect the embedded message
 							*/
 							/* In this case we do not want the columns updated */
-							col_set_writable(pinfo->cinfo, FALSE);
+							col_set_writable(pinfo->cinfo, -1, FALSE);
 							call_dissector(handle, l3_tvb, pinfo, pco_tree);
-							col_set_writable(pinfo->cinfo, TRUE);
+							col_set_writable(pinfo->cinfo, -1, TRUE);
 						}
 						else
 						{
diff --git a/epan/dissectors/packet-gsm_sms_ud.c b/epan/dissectors/packet-gsm_sms_ud.c
index 3efc54e37e..d98b3c364e 100644
--- a/epan/dissectors/packet-gsm_sms_ud.c
+++ b/epan/dissectors/packet-gsm_sms_ud.c
@@ -458,9 +458,9 @@ parse_gsm_sms_ud_message(proto_tree *sm_tree, tvbuff_t *tvb, packet_info *pinfo,
             if (ports_available) {
                 gboolean disallow_write = FALSE; /* TRUE if we changed writability
                                     of the columns of the summary */
-                if (prevent_subdissectors_changing_columns && col_get_writable(pinfo->cinfo)) {
+                if (prevent_subdissectors_changing_columns && col_get_writable(pinfo->cinfo, -1)) {
                     disallow_write = TRUE;
-                    col_set_writable(pinfo->cinfo, FALSE);
+                    col_set_writable(pinfo->cinfo, -1, FALSE);
                 }
 
                 if (port_number_udh_means_wsp) {
@@ -478,7 +478,7 @@ parse_gsm_sms_ud_message(proto_tree *sm_tree, tvbuff_t *tvb, packet_info *pinfo,
                 }
 
                 if (disallow_write)
-                    col_set_writable(pinfo->cinfo, TRUE);
+                    col_set_writable(pinfo->cinfo, -1, TRUE);
             } else { /* No ports IE */
                 proto_tree_add_item(sm_tree, hf_gsm_sms_ud_short_msg, sm_tvb, 0, -1, ENC_NA);
             }
diff --git a/epan/dissectors/packet-ipsec.c b/epan/dissectors/packet-ipsec.c
index a9b8d25df9..8643c92957 100644
--- a/epan/dissectors/packet-ipsec.c
+++ b/epan/dissectors/packet-ipsec.c
@@ -1202,7 +1202,7 @@ dissect_ah(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
   next_tvb = tvb_new_subset_remaining(tvb, advance);
 
   if (g_ah_payload_in_subtree) {
-    col_set_writable(pinfo->cinfo, FALSE);
+    col_set_writable(pinfo->cinfo, -1, FALSE);
   }
 
   /* do lookup with the subdissector table */
diff --git a/epan/dissectors/packet-jxta.c b/epan/dissectors/packet-jxta.c
index 465c18ff62..65379a447a 100644
--- a/epan/dissectors/packet-jxta.c
+++ b/epan/dissectors/packet-jxta.c
@@ -1006,7 +1006,7 @@ static int dissect_jxta_welcome(tvbuff_t * tvb, packet_info * pinfo, proto_tree
 Common_Exit:
     g_strfreev(tokens);
 
-    col_set_writable(pinfo->cinfo, FALSE);
+    col_set_writable(pinfo->cinfo, -1, FALSE);
 
     return afterwelcome;
 }
@@ -1363,7 +1363,7 @@ static int dissect_jxta_message(tvbuff_t * tvb, packet_info * pinfo, proto_tree
                      wmem_strbuf_get_str(src_addr), wmem_strbuf_get_str(dst_addr));
     }
 
-    col_set_writable(pinfo->cinfo, FALSE);
+    col_set_writable(pinfo->cinfo, -1, FALSE);
 
     while( tree && (complete_messages > 0) ) {
         proto_item *jxta_msg_tree_item = NULL;
diff --git a/epan/dissectors/packet-knet.c b/epan/dissectors/packet-knet.c
index dc8f127ad8..6640a7a1a6 100644
--- a/epan/dissectors/packet-knet.c
+++ b/epan/dissectors/packet-knet.c
@@ -353,7 +353,6 @@ dissect_messageid(tvbuff_t *buffer, int *offset, proto_tree *tree, packet_info *
 {
     gint   messageid_length;
     guint8 messageid;
-    gboolean col_write;
 
     messageid = tvb_get_guint8(buffer, (*offset));
 
@@ -374,16 +373,9 @@ dissect_messageid(tvbuff_t *buffer, int *offset, proto_tree *tree, packet_info *
     proto_tree_add_uint_format_value(tree, hf_knet_messageid, buffer, *offset, messageid_length, messageid,
             "%s (%d)", val_to_str_const(messageid, packettypenames, "AppData or Malformed Message ID"), messageid);
 
-    /* XXX - TCP reassembly disables writing columns which prevents populating COL_INFO if multiple KNET messages
-       appear in a single packet that needed to be reassembled.
-       Force making columns writable.
-    */
     if (separator)
     {
-        col_write = col_get_writable(pinfo->cinfo);
-        col_set_writable(pinfo->cinfo, TRUE);
         col_append_sep_fstr(pinfo->cinfo, COL_INFO, ", ", "%s (%d)", val_to_str_const(messageid, packettypenames, "AppData"), messageid);
-        col_set_writable(pinfo->cinfo, col_write);
     }
     else
     {
diff --git a/epan/dissectors/packet-lte-rrc.c b/epan/dissectors/packet-lte-rrc.c
index db0990ce7f..0b6dc9c8cf 100644
--- a/epan/dissectors/packet-lte-rrc.c
+++ b/epan/dissectors/packet-lte-rrc.c
@@ -59287,13 +59287,13 @@ dissect_lte_rrc_Handover_Preparation_Info(tvbuff_t *tvb, packet_info *pinfo, pro
   /* Don't want elements inside message updating Info column, so set now and
      freeze during dissection of PDU */
   col_set_str(pinfo->cinfo, COL_INFO, "HandoverPreparationInformation");
-  col_set_writable(pinfo->cinfo, FALSE);
+  col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
 
   ti = proto_tree_add_item(tree, proto_lte_rrc, tvb, 0, -1, ENC_NA);
   lte_rrc_tree = proto_item_add_subtree(ti, ett_lte_rrc);
   dissect_lte_rrc_HandoverPreparationInformation_PDU(tvb, pinfo, lte_rrc_tree, NULL);
 
-  col_set_writable(pinfo->cinfo, TRUE);
+  col_set_writable(pinfo->cinfo, COL_INFO, TRUE);
   return tvb_captured_length(tvb);
 }
 
diff --git a/epan/dissectors/packet-mac-lte.c b/epan/dissectors/packet-mac-lte.c
index 6525867655..d499b4ce73 100644
--- a/epan/dissectors/packet-mac-lte.c
+++ b/epan/dissectors/packet-mac-lte.c
@@ -2583,7 +2583,7 @@ static void show_extra_phy_parameters(packet_info *pinfo, tvbuff_t *tvb, proto_t
 
             /* Don't want columns to be replaced now */
             if (global_mac_lte_layer_to_show == ShowPHYLayer) {
-                col_set_writable(pinfo->cinfo, FALSE);
+                col_set_writable(pinfo->cinfo, -1, FALSE);
             }
         }
     }
@@ -2670,7 +2670,7 @@ static void show_extra_phy_parameters(packet_info *pinfo, tvbuff_t *tvb, proto_t
 
             /* Don't want columns to be replaced now */
             if (global_mac_lte_layer_to_show == ShowPHYLayer) {
-                col_set_writable(pinfo->cinfo, FALSE);
+                col_set_writable(pinfo->cinfo, -1, FALSE);
             }
         }
     }
@@ -3169,7 +3169,7 @@ static void call_rlc_dissector(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tr
 
     if (global_mac_lte_layer_to_show != ShowRLCLayer) {
         /* Don't want these columns replaced */
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, -1, FALSE);
     }
     else {
         /* Clear info column before first RLC PDU */
@@ -3188,7 +3188,7 @@ static void call_rlc_dissector(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tr
     call_with_catch_all(rlc_lte_handle, rb_tvb, pinfo, tree);
 
     /* Let columns be written to again */
-    col_set_writable(pinfo->cinfo, TRUE);
+    col_set_writable(pinfo->cinfo, -1, TRUE);
 }
 
 
diff --git a/epan/dissectors/packet-mint.c b/epan/dissectors/packet-mint.c
index 8c3b34c68a..32cc2d2f4f 100644
--- a/epan/dissectors/packet-mint.c
+++ b/epan/dissectors/packet-mint.c
@@ -284,7 +284,7 @@ dissect_eth_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *mint_tree,
 	tvbuff_t *eth_tvb;
 
 #ifdef MINT_DEVELOPMENT
-	col_set_writable(pinfo->cinfo, FALSE);
+	col_set_writable(pinfo->cinfo, -1, FALSE);
 #endif
 
 	eth_tvb = tvb_new_subset_length(tvb, offset, length);
@@ -297,7 +297,7 @@ dissect_eth_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *mint_tree,
 	offset += length;
 
 #ifdef MINT_DEVELOPMENT
-	col_set_writable(pinfo->cinfo, TRUE);
+	col_set_writable(pinfo->cinfo, -1, TRUE);
 #endif
 	return offset;
 }
diff --git a/epan/dissectors/packet-msdp.c b/epan/dissectors/packet-msdp.c
index 9a76c31d28..081c6cde24 100644
--- a/epan/dissectors/packet-msdp.c
+++ b/epan/dissectors/packet-msdp.c
@@ -316,7 +316,7 @@ static void dissect_msdp_sa(tvbuff_t *tvb, packet_info *pinfo,
                  * reflect the MSDP packet rather than the
                  * encapsulated packet.
                  */
-                col_set_writable(pinfo->cinfo, FALSE);
+                col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
                 call_dissector(ip_handle, next_tvb, pinfo, enc_tree);
         }
         *offset += length;
diff --git a/epan/dissectors/packet-ndmp.c b/epan/dissectors/packet-ndmp.c
index 1fe64719d2..f3f0d4600d 100644
--- a/epan/dissectors/packet-ndmp.c
+++ b/epan/dissectors/packet-ndmp.c
@@ -2991,7 +2991,7 @@ dissect_ndmp_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void*
 	wmem_map_t *frags;
 	conversation_t *conversation;
 	proto_item *vers_item;
-	gboolean save_fragmented, save_writable;
+	gboolean save_fragmented, save_info_writable, save_proto_writable;
 	gboolean do_frag = TRUE;
 	tvbuff_t* new_tvb = NULL;
 	fragment_head *frag_msg = NULL;
@@ -3212,8 +3212,10 @@ dissect_ndmp_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void*
 	 * multiple fragments, the column becomes unwritable.
 	 * Temporarily change that so that the correct header can be
 	 * applied */
-	save_writable = col_get_writable(pinfo->cinfo);
-	col_set_writable(pinfo->cinfo, TRUE);
+	save_info_writable = col_get_writable(pinfo->cinfo, COL_INFO);
+	save_proto_writable = col_get_writable(pinfo->cinfo, COL_PROTOCOL);
+	col_set_writable(pinfo->cinfo, COL_PROTOCOL, TRUE);
+	col_set_writable(pinfo->cinfo, COL_INFO, TRUE);
 
 	col_set_str(pinfo->cinfo, COL_PROTOCOL, "NDMP");
 	col_clear(pinfo->cinfo, COL_INFO);
@@ -3292,7 +3294,8 @@ dissect_ndmp_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void*
 
 	/* restore saved variables */
 	pinfo->fragmented = save_fragmented;
-	col_set_writable(pinfo->cinfo, save_writable);
+	col_set_writable(pinfo->cinfo, COL_INFO, save_info_writable);
+	col_set_writable(pinfo->cinfo, COL_PROTOCOL, save_proto_writable);
 
 	return tvb_captured_length(tvb);
 }
diff --git a/epan/dissectors/packet-openflow_v1.c b/epan/dissectors/packet-openflow_v1.c
index 41c9bd62df..52f89b83f2 100644
--- a/epan/dissectors/packet-openflow_v1.c
+++ b/epan/dissectors/packet-openflow_v1.c
@@ -838,7 +838,7 @@ dissect_openflow_v1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *d
 
     /* Stop the Ethernet frame from overwriting the columns */
     if((type == OFPT_1_0_PACKET_IN) || (type == OFPT_1_0_PACKET_OUT)){
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, -1, FALSE);
     }
 
     /* Create display subtree for the protocol */
diff --git a/epan/dissectors/packet-openflow_v4.c b/epan/dissectors/packet-openflow_v4.c
index 97efeb322e..1d84e6d9f3 100644
--- a/epan/dissectors/packet-openflow_v4.c
+++ b/epan/dissectors/packet-openflow_v4.c
@@ -1819,7 +1819,7 @@ dissect_openflow_packet_in_v4(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree
         data_tree = proto_tree_add_subtree(tree, tvb, offset, length - offset, ett_openflow_v4_packet_in_data, NULL, "Data");
 
         /* save some state */
-        save_writable = col_get_writable(pinfo->cinfo);
+        save_writable = col_get_writable(pinfo->cinfo, -1);
         save_in_error_pkt = pinfo->flags.in_error_pkt;
         copy_address_shallow(&save_dl_src, &pinfo->dl_src);
         copy_address_shallow(&save_dl_dst, &pinfo->dl_dst);
@@ -1829,12 +1829,12 @@ dissect_openflow_packet_in_v4(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree
         copy_address_shallow(&save_dst, &pinfo->dst);
 
         /* dissect data */
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, -1, FALSE);
         next_tvb = tvb_new_subset_length(tvb, offset, length - offset);
         call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, data_tree);
 
         /* restore saved state */
-        col_set_writable(pinfo->cinfo, save_writable);
+        col_set_writable(pinfo->cinfo, -1, save_writable);
         pinfo->flags.in_error_pkt = save_in_error_pkt;
         copy_address_shallow(&pinfo->dl_src, &save_dl_src);
         copy_address_shallow(&pinfo->dl_dst, &save_dl_dst);
@@ -2406,7 +2406,7 @@ dissect_openflow_packet_out_v4(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree
         data_tree = proto_tree_add_subtree(tree, tvb, offset, length - offset, ett_openflow_v4_packet_out_data, NULL, "Data");
 
         /* save some state */
-        save_writable = col_get_writable(pinfo->cinfo);
+        save_writable = col_get_writable(pinfo->cinfo, -1);
         save_in_error_pkt = pinfo->flags.in_error_pkt;
         copy_address_shallow(&save_dl_src, &pinfo->dl_src);
         copy_address_shallow(&save_dl_dst, &pinfo->dl_dst);
@@ -2416,12 +2416,12 @@ dissect_openflow_packet_out_v4(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree
         copy_address_shallow(&save_dst, &pinfo->dst);
 
         /* dissect data */
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, -1, FALSE);
         next_tvb = tvb_new_subset_length(tvb, offset, length - offset);
         call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, data_tree);
 
         /* restore saved state */
-        col_set_writable(pinfo->cinfo, save_writable);
+        col_set_writable(pinfo->cinfo, -1, save_writable);
         pinfo->flags.in_error_pkt = save_in_error_pkt;
         copy_address_shallow(&pinfo->dl_src, &save_dl_src);
         copy_address_shallow(&pinfo->dl_dst, &save_dl_dst);
diff --git a/epan/dissectors/packet-openflow_v5.c b/epan/dissectors/packet-openflow_v5.c
index 1822f673c5..cc9d9d4d4e 100644
--- a/epan/dissectors/packet-openflow_v5.c
+++ b/epan/dissectors/packet-openflow_v5.c
@@ -2049,7 +2049,7 @@ dissect_openflow_packet_in_v5(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree
         data_tree = proto_tree_add_subtree(tree, tvb, offset, length - offset, ett_openflow_v5_packet_in_data, NULL, "Data");
 
         /* save some state */
-        save_writable = col_get_writable(pinfo->cinfo);
+        save_writable = col_get_writable(pinfo->cinfo, -1);
         save_in_error_pkt = pinfo->flags.in_error_pkt;
         copy_address_shallow(&save_dl_src, &pinfo->dl_src);
         copy_address_shallow(&save_dl_dst, &pinfo->dl_dst);
@@ -2059,12 +2059,12 @@ dissect_openflow_packet_in_v5(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree
         copy_address_shallow(&save_dst, &pinfo->dst);
 
         /* dissect data */
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, -1, FALSE);
         next_tvb = tvb_new_subset_length(tvb, offset, length - offset);
         call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, data_tree);
 
         /* restore saved state */
-        col_set_writable(pinfo->cinfo, save_writable);
+        col_set_writable(pinfo->cinfo, -1, save_writable);
         pinfo->flags.in_error_pkt = save_in_error_pkt;
         copy_address_shallow(&pinfo->dl_src, &save_dl_src);
         copy_address_shallow(&pinfo->dl_dst, &save_dl_dst);
@@ -2788,7 +2788,7 @@ dissect_openflow_packet_out_v5(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree
         data_tree = proto_tree_add_subtree(tree, tvb, offset, length - offset, ett_openflow_v5_packet_out_data, NULL, "Data");
 
         /* save some state */
-        save_writable = col_get_writable(pinfo->cinfo);
+        save_writable = col_get_writable(pinfo->cinfo, -1);
         save_in_error_pkt = pinfo->flags.in_error_pkt;
         copy_address_shallow(&save_dl_src, &pinfo->dl_src);
         copy_address_shallow(&save_dl_dst, &pinfo->dl_dst);
@@ -2798,12 +2798,12 @@ dissect_openflow_packet_out_v5(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree
         copy_address_shallow(&save_dst, &pinfo->dst);
 
         /* dissect data */
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, -1, FALSE);
         next_tvb = tvb_new_subset_length(tvb, offset, length - offset);
         call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, data_tree);
 
         /* restore saved state */
-        col_set_writable(pinfo->cinfo, save_writable);
+        col_set_writable(pinfo->cinfo, -1, save_writable);
         pinfo->flags.in_error_pkt = save_in_error_pkt;
         copy_address_shallow(&pinfo->dl_src, &save_dl_src);
         copy_address_shallow(&pinfo->dl_dst, &save_dl_dst);
diff --git a/epan/dissectors/packet-pdcp-lte.c b/epan/dissectors/packet-pdcp-lte.c
index b0455bbdac..42da3f239f 100644
--- a/epan/dissectors/packet-pdcp-lte.c
+++ b/epan/dissectors/packet-pdcp-lte.c
@@ -1740,12 +1740,12 @@ static int dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
     if ((global_pdcp_lte_layer_to_show == ShowRLCLayer) &&
         (p_get_proto_data(wmem_file_scope(), pinfo, proto_rlc_lte, 0) != NULL)) {
 
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
     }
     else {
         /* TODO: won't help with multiple PDCP-or-traffic PDUs / frame... */
         col_clear(pinfo->cinfo, COL_INFO);
-        col_set_writable(pinfo->cinfo, TRUE);
+        col_set_writable(pinfo->cinfo, COL_INFO, TRUE);
     }
 
     /* Create pdcp tree. */
@@ -2263,15 +2263,15 @@ static int dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
             if (rrc_handle != 0) {
                 /* Call RRC dissector if have one */
                 tvbuff_t *rrc_payload_tvb = tvb_new_subset_length(payload_tvb, offset, data_length);
-                gboolean was_writable = col_get_writable(pinfo->cinfo);
+                gboolean was_writable = col_get_writable(pinfo->cinfo, COL_INFO);
 
                 /* We always want to see this in the info column */
-                col_set_writable(pinfo->cinfo, TRUE);
+                col_set_writable(pinfo->cinfo, COL_INFO, TRUE);
 
                 call_dissector_only(rrc_handle, rrc_payload_tvb, pinfo, pdcp_tree, NULL);
 
                 /* Restore to whatever it was */
-                col_set_writable(pinfo->cinfo, was_writable);
+                col_set_writable(pinfo->cinfo, COL_INFO, was_writable);
             }
             else {
                  /* Just show data */
@@ -2338,7 +2338,7 @@ static int dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 
                         /* Don't update info column for ROHC unless configured to */
                         if (global_pdcp_lte_layer_to_show != ShowTrafficLayer) {
-                            col_set_writable(pinfo->cinfo, FALSE);
+                            col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
                         }
 
                         switch (tvb_get_guint8(ip_payload_tvb, 0) & 0xf0) {
@@ -2355,7 +2355,7 @@ static int dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 
                         /* Freeze the columns again because we don't want other layers writing to info */
                         if (global_pdcp_lte_layer_to_show == ShowTrafficLayer) {
-                            col_set_writable(pinfo->cinfo, FALSE);
+                            col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
                         }
 
                     }
@@ -2371,7 +2371,7 @@ static int dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
             /* (there will be no signalling data left at this point) */
 
             /* Let RLC write to columns again */
-            col_set_writable(pinfo->cinfo, global_pdcp_lte_layer_to_show == ShowRLCLayer);
+            col_set_writable(pinfo->cinfo, COL_INFO, global_pdcp_lte_layer_to_show == ShowRLCLayer);
 
             /* DROPPING OUT HERE IF NOT DOING ROHC! */
             return tvb_captured_length(tvb);
@@ -2392,7 +2392,7 @@ static int dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 
             /* Only enable writing to column if configured to show ROHC */
             if (global_pdcp_lte_layer_to_show != ShowTrafficLayer) {
-                col_set_writable(pinfo->cinfo, FALSE);
+                col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
             }
             else {
                 col_clear(pinfo->cinfo, COL_INFO);
@@ -2402,7 +2402,7 @@ static int dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
             call_dissector_with_data(rohc_handle, rohc_tvb, pinfo, tree, &p_pdcp_info->rohc);
 
             /* Let RLC write to columns again */
-            col_set_writable(pinfo->cinfo, global_pdcp_lte_layer_to_show == ShowRLCLayer);
+            col_set_writable(pinfo->cinfo, COL_INFO, global_pdcp_lte_layer_to_show == ShowRLCLayer);
         }
     }
     return tvb_captured_length(tvb);
diff --git a/epan/dissectors/packet-pim.c b/epan/dissectors/packet-pim.c
index ac0c299c37..f2257dc8c2 100644
--- a/epan/dissectors/packet-pim.c
+++ b/epan/dissectors/packet-pim.c
@@ -388,7 +388,7 @@ dissect_pimv1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U
          * explicitly state that.
          */
         pim_length = 8;
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, -1, FALSE);
     } else {
         /*
          * Other message - checksum the entire packet.
@@ -874,7 +874,7 @@ dissect_pim(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
          * this register will overwrite the PIM info in the columns.
          */
         pim_length = 8;
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, -1, FALSE);
     } else {
         /*
          * Other message - checksum the entire packet.
diff --git a/epan/dissectors/packet-portmap.c b/epan/dissectors/packet-portmap.c
index 1e578bde2f..e990cc94c0 100644
--- a/epan/dissectors/packet-portmap.c
+++ b/epan/dissectors/packet-portmap.c
@@ -304,7 +304,7 @@ dissect_callit_call(tvbuff_t *tvb, packet_info *pinfo,
 	/* Dissect the arguments for this procedure.
 	   Make the columns non-writable, so the dissector won't change
 	   them out from under us. */
-	col_set_writable(pinfo->cinfo, FALSE);
+	col_set_writable(pinfo->cinfo, -1, FALSE);
 	offset = dissect_rpc_indir_call(tvb, pinfo, tree, offset,
 		hf_portmap_args, prog, vers, proc);
 
@@ -325,7 +325,7 @@ dissect_callit_reply(tvbuff_t *tvb, packet_info *pinfo,
 	/* Dissect the result of this procedure.
 	   Make the columns non-writable, so the dissector won't change
 	   them out from under us. */
-	col_set_writable(pinfo->cinfo, FALSE);
+	col_set_writable(pinfo->cinfo, -1, FALSE);
 	offset = dissect_rpc_indir_reply(tvb, pinfo, tree, offset,
 		hf_portmap_result, hf_portmap_prog, hf_portmap_version,
 		hf_portmap_proc);
@@ -460,7 +460,7 @@ dissect_rpcb_rmtcallres(tvbuff_t *tvb, packet_info *pinfo _U_,
 	/* Dissect the result of this procedure.
 	   Make the columns non-writable, so the dissector won't change
 	   them out from under us. */
-	col_set_writable(pinfo->cinfo, FALSE);
+	col_set_writable(pinfo->cinfo, -1, FALSE);
 	offset = dissect_rpc_indir_reply(tvb, pinfo, tree, offset,
 		hf_portmap_result, hf_portmap_prog, hf_portmap_version,
 		hf_portmap_proc);
diff --git a/epan/dissectors/packet-radius.c b/epan/dissectors/packet-radius.c
index 6202f162e0..c0b1ff5945 100644
--- a/epan/dissectors/packet-radius.c
+++ b/epan/dissectors/packet-radius.c
@@ -1701,12 +1701,12 @@ dissect_attribute_value_pairs(proto_tree *tree, packet_info *pinfo, tvbuff_t *tv
 					 * this as an RADIUS packet, not
 					 * as an EAP packet.
 					 */
-					save_writable = col_get_writable(pinfo->cinfo);
-					col_set_writable(pinfo->cinfo, FALSE);
+					save_writable = col_get_writable(pinfo->cinfo, -1);
+					col_set_writable(pinfo->cinfo, -1, FALSE);
 
 					call_dissector(eap_handle, eap_tvb, pinfo, eap_tree);
 
-					col_set_writable(pinfo->cinfo, save_writable);
+					col_set_writable(pinfo->cinfo, -1, save_writable);
 				} else {
 					proto_item_append_text(avp_item, " Segment[%u]",
 							       eap_seg_num);
diff --git a/epan/dissectors/packet-rlc.c b/epan/dissectors/packet-rlc.c
index 281e5a3386..e346a9075b 100644
--- a/epan/dissectors/packet-rlc.c
+++ b/epan/dissectors/packet-rlc.c
@@ -1322,7 +1322,7 @@ rlc_call_subdissector(enum rlc_channel_type channel, tvbuff_t *tvb,
             /* assume transparent PDCP for now */
             call_dissector(ip_handle, tvb, pinfo, tree);
             /* once the packet has been dissected, protect it from further changes */
-            col_set_writable(pinfo->cinfo, FALSE);
+            col_set_writable(pinfo->cinfo, -1, FALSE);
             break;
         default:
             return; /* stop dissecting */
@@ -1339,7 +1339,7 @@ rlc_call_subdissector(enum rlc_channel_type channel, tvbuff_t *tvb,
         rrcinf->msgtype[fpinf->cur_tb] = msgtype;
         call_dissector(rrc_handle, tvb, pinfo, tree);
         /* once the packet has been dissected, protect it from further changes */
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, -1, FALSE);
     }
 }
 
diff --git a/epan/dissectors/packet-rtsp.c b/epan/dissectors/packet-rtsp.c
index 27996976c3..6858be26bf 100644
--- a/epan/dissectors/packet-rtsp.c
+++ b/epan/dissectors/packet-rtsp.c
@@ -1376,10 +1376,10 @@ dissect_rtsp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_
 
         /*
          * OK, we've set the Protocol and Info columns for the
-         * first RTSP message; make the columns non-writable,
-         * so that we don't change it for subsequent RTSP messages.
+         * first RTSP message; set fence so changes are kept for
+         * subsequent RTSP messages.
          */
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_fence(pinfo->cinfo, COL_INFO);
     }
     return tvb_captured_length(tvb);
 }
diff --git a/epan/dissectors/packet-s1ap.c b/epan/dissectors/packet-s1ap.c
index 3bcc1e484e..93f822f5e4 100644
--- a/epan/dissectors/packet-s1ap.c
+++ b/epan/dissectors/packet-s1ap.c
@@ -6002,7 +6002,7 @@ dissect_s1ap_Source_ToTarget_TransparentContainer(tvbuff_t *tvb _U_, int offset
 
 	if (g_s1ap_dissect_container) {
 		/* Don't want elements inside container to write to info column */
-		col_set_writable(actx->pinfo->cinfo, FALSE);
+		col_set_writable(actx->pinfo->cinfo, COL_INFO, FALSE);
 		subtree = proto_item_add_subtree(actx->created_item, ett_s1ap_ToTargetTransparentContainer);
 
     	switch(handover_type_value){
@@ -6047,7 +6047,7 @@ dissect_s1ap_Source_ToTarget_TransparentContainer(tvbuff_t *tvb _U_, int offset
 			break;
 		}
 		/* Enable writing of the column again */
-		col_set_writable(actx->pinfo->cinfo, TRUE);
+		col_set_writable(actx->pinfo->cinfo, COL_INFO, TRUE);
 	}
 
 
diff --git a/epan/dissectors/packet-sctp.c b/epan/dissectors/packet-sctp.c
index 7baf3a9ee0..fb7e32e1ad 100644
--- a/epan/dissectors/packet-sctp.c
+++ b/epan/dissectors/packet-sctp.c
@@ -4447,9 +4447,9 @@ dissect_sctp_chunk(tvbuff_t *chunk_tvb,
     dissect_i_forward_tsn_chunk(chunk_tvb, length, chunk_tree, chunk_item);
     break;
   case SCTP_PKTDROP_CHUNK_ID:
-    col_set_writable(pinfo->cinfo, FALSE);
+    col_set_writable(pinfo->cinfo, -1, FALSE);
     dissect_pktdrop_chunk(chunk_tvb, length, pinfo, chunk_tree, chunk_item, flags_item);
-    col_set_writable(pinfo->cinfo, TRUE);
+    col_set_writable(pinfo->cinfo, -1, TRUE);
     break;
   case SCTP_PAD_CHUNK_ID:
     dissect_pad_chunk(chunk_tvb, length, chunk_tree, chunk_item);
diff --git a/epan/dissectors/packet-sflow.c b/epan/dissectors/packet-sflow.c
index 991f283e8c..6c9206db6f 100644
--- a/epan/dissectors/packet-sflow.c
+++ b/epan/dissectors/packet-sflow.c
@@ -679,7 +679,7 @@ dissect_sflow_245_sampled_header(tvbuff_t *tvb, packet_info *pinfo,
     next_tvb = tvb_new_subset(tvb, offset, header_length, frame_length);
 
     /* save some state */
-    save_writable = col_get_writable(pinfo->cinfo);
+    save_writable = col_get_writable(pinfo->cinfo, -1);
 
     /*
        If sFlow samples a TCP packet it is very likely that the
@@ -705,7 +705,7 @@ dissect_sflow_245_sampled_header(tvbuff_t *tvb, packet_info *pinfo,
         pinfo->flags.in_error_pkt = TRUE;
     }
 
-    col_set_writable(pinfo->cinfo, FALSE);
+    col_set_writable(pinfo->cinfo, -1, FALSE);
     copy_address_shallow(&save_dl_src, &pinfo->dl_src);
     copy_address_shallow(&save_dl_dst, &pinfo->dl_dst);
     copy_address_shallow(&save_net_src, &pinfo->net_src);
@@ -727,7 +727,7 @@ dissect_sflow_245_sampled_header(tvbuff_t *tvb, packet_info *pinfo,
     ENDTRY;
 
     /* restore saved state */
-    col_set_writable(pinfo->cinfo, save_writable);
+    col_set_writable(pinfo->cinfo, -1, save_writable);
     pinfo->flags.in_error_pkt = save_in_error_pkt;
     copy_address_shallow(&pinfo->dl_src, &save_dl_src);
     copy_address_shallow(&pinfo->dl_dst, &save_dl_dst);
diff --git a/epan/dissectors/packet-ssl.c b/epan/dissectors/packet-ssl.c
index 6bab404798..1cbbe939c8 100644
--- a/epan/dissectors/packet-ssl.c
+++ b/epan/dissectors/packet-ssl.c
@@ -1095,12 +1095,11 @@ again:
             int old_len;
 
             /*
-             * Unblock and reset column in case multiple SSL segments form the
+             * Reset column in case multiple SSL segments form the
              * PDU and this last SSL segment is not in the first TCP segment of
              * this frame.
              * XXX prevent clearing the column if the last layer is not SSL?
              */
-            col_set_writable(pinfo->cinfo, TRUE);
             /* Clear column during the first pass. */
             col_clear(pinfo->cinfo, COL_INFO);
 
@@ -1339,11 +1338,9 @@ again:
          * PROTOCOL and INFO colums since what follows may be an
          * incomplete PDU and we don't want it be changed back from
          *  <Protocol>   to <TCP>
-         * XXX There is no good way to block the PROTOCOL column
-         * from being changed yet so we set the entire row unwritable.
          */
         col_set_fence(pinfo->cinfo, COL_INFO);
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, COL_PROTOCOL, FALSE);
         offset += another_pdu_follows;
         seq += another_pdu_follows;
         goto again;
diff --git a/epan/dissectors/packet-tcp.c b/epan/dissectors/packet-tcp.c
index 73399e12d1..ac7d9217a0 100644
--- a/epan/dissectors/packet-tcp.c
+++ b/epan/dissectors/packet-tcp.c
@@ -2487,7 +2487,7 @@ desegment_tcp(tvbuff_t *tvb, packet_info *pinfo, int offset,
     gint nbytes;
     proto_item *item;
     struct tcp_multisegment_pdu *msp;
-    gboolean cleared_writable = col_get_writable(pinfo->cinfo);
+    gboolean cleared_writable = col_get_writable(pinfo->cinfo, COL_PROTOCOL);
 
 again:
     ipfd_head = NULL;
@@ -2932,13 +2932,10 @@ again:
          * PROTOCOL and INFO columns since what follows may be an
          * incomplete PDU and we don't want it be changed back from
          *  <Protocol>   to <TCP>
-         * XXX There is no good way to block the PROTOCOL column
-         * from being changed yet so we set the entire row unwritable.
-         * The flag cleared_writable stores the initial state.
          */
         col_set_fence(pinfo->cinfo, COL_INFO);
-        cleared_writable |= col_get_writable(pinfo->cinfo);
-        col_set_writable(pinfo->cinfo, FALSE);
+        cleared_writable |= col_get_writable(pinfo->cinfo, COL_PROTOCOL);
+        col_set_writable(pinfo->cinfo, COL_PROTOCOL, FALSE);
         offset += another_pdu_follows;
         seq += another_pdu_follows;
         goto again;
@@ -2947,7 +2944,7 @@ again:
          * proto,colinfo tap will break
          */
         if(cleared_writable) {
-            col_set_writable(pinfo->cinfo, TRUE);
+            col_set_writable(pinfo->cinfo, COL_PROTOCOL, TRUE);
         }
     }
 }
diff --git a/epan/dissectors/packet-wassp.c b/epan/dissectors/packet-wassp.c
index a3c6f86ddf..527c785d59 100644
--- a/epan/dissectors/packet-wassp.c
+++ b/epan/dissectors/packet-wassp.c
@@ -773,7 +773,7 @@ dissect_snmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *wassp_tree,
 	tvbuff_t *snmp_tvb;
 
 	/* Don't add SNMP stuff to the info column */
-	col_set_writable(pinfo->cinfo, FALSE);
+	col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
 
 	snmp_tvb = tvb_new_subset_length(tvb, offset, length);
 
@@ -784,7 +784,7 @@ dissect_snmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *wassp_tree,
 		show_exception(snmp_tvb, pinfo, wassp_tree, EXCEPT_CODE, GET_MESSAGE);
 	} ENDTRY;
 
-	col_set_writable(pinfo->cinfo, TRUE);
+	col_set_writable(pinfo->cinfo, COL_INFO, TRUE);
 
 	offset += length;
 
@@ -798,7 +798,7 @@ dissect_ieee80211(tvbuff_t *tvb, packet_info *pinfo, proto_tree *wassp_tree,
 	tvbuff_t *ieee80211_tvb;
 
 	/* Don't add IEEE 802.11 stuff to the info column */
-	col_set_writable(pinfo->cinfo, FALSE);
+	col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
 
 	ieee80211_tvb = tvb_new_subset_length(tvb, offset, length);
 
@@ -809,7 +809,7 @@ dissect_ieee80211(tvbuff_t *tvb, packet_info *pinfo, proto_tree *wassp_tree,
 		show_exception(ieee80211_tvb, pinfo, wassp_tree, EXCEPT_CODE, GET_MESSAGE);
 	} ENDTRY;
 
-	col_set_writable(pinfo->cinfo, TRUE);
+	col_set_writable(pinfo->cinfo, COL_INFO, TRUE);
 
 	offset += length;
 
diff --git a/epan/dissectors/packet-zbee-zcl-general.c b/epan/dissectors/packet-zbee-zcl-general.c
index 45bcadf7df..611306f963 100644
--- a/epan/dissectors/packet-zbee-zcl-general.c
+++ b/epan/dissectors/packet-zbee-zcl-general.c
@@ -12679,18 +12679,18 @@ dissect_zbee_zcl_gp_payload(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 
     if (payload_size != 0 && payload_size != 0xff) {
         tvbuff_t *gtvb = tvb_new_composite();
-        gboolean writable = col_get_writable(pinfo->cinfo);
+        gboolean writable = col_get_writable(pinfo->cinfo, COL_INFO);
 
         /* remove payload length and put command id instead */
         tvb_composite_append(gtvb, tvb_new_subset_length(tvb, offset-2, 1));
         tvb_composite_append(gtvb, tvb_new_subset_length(tvb, offset, payload_size));
         tvb_composite_finalize(gtvb);
         /* prevent overwriting COL_INFO */
-        col_set_writable(pinfo->cinfo, FALSE);
+        col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
         /* Actually dissect_zbee_nwk_gp_cmd wants zbee_nwk_green_power_packet*
          * as a data but never uses it. */
         call_dissector_only(zgp_handle, gtvb, pinfo, tree, NULL);
-        col_set_writable(pinfo->cinfo, writable);
+        col_set_writable(pinfo->cinfo, COL_INFO, writable);
         offset += payload_size;
     }
     return offset;
diff --git a/epan/packet.c b/epan/packet.c
index 21ea2d2b88..8deef8fdef 100644
--- a/epan/packet.c
+++ b/epan/packet.c
@@ -782,8 +782,8 @@ call_dissector_work_error(dissector_handle_t handle, tvbuff_t *tvb,
 	saved_proto = pinfo->current_proto;
 	saved_can_desegment = pinfo->can_desegment;
 
-	save_writable = col_get_writable(pinfo->cinfo);
-	col_set_writable(pinfo->cinfo, FALSE);
+	save_writable = col_get_writable(pinfo->cinfo, -1);
+	col_set_writable(pinfo->cinfo, -1, FALSE);
 	copy_address_shallow(&save_dl_src, &pinfo->dl_src);
 	copy_address_shallow(&save_dl_dst, &pinfo->dl_dst);
 	copy_address_shallow(&save_net_src, &pinfo->net_src);
@@ -799,7 +799,7 @@ call_dissector_work_error(dissector_handle_t handle, tvbuff_t *tvb,
 		/*
 		* Restore the column writability and addresses.
 		*/
-		col_set_writable(pinfo->cinfo, save_writable);
+		col_set_writable(pinfo->cinfo, -1, save_writable);
 		copy_address_shallow(&pinfo->dl_src, &save_dl_src);
 		copy_address_shallow(&pinfo->dl_dst, &save_dl_dst);
 		copy_address_shallow(&pinfo->net_src, &save_net_src);
@@ -841,7 +841,7 @@ call_dissector_work_error(dissector_handle_t handle, tvbuff_t *tvb,
 	}
 	ENDTRY;
 
-	col_set_writable(pinfo->cinfo, save_writable);
+	col_set_writable(pinfo->cinfo, -1, save_writable);
 	copy_address_shallow(&pinfo->dl_src, &save_dl_src);
 	copy_address_shallow(&pinfo->dl_dst, &save_dl_dst);
 	copy_address_shallow(&pinfo->net_src, &save_net_src);
diff --git a/plugins/wimaxasncp/packet-wimaxasncp.c b/plugins/wimaxasncp/packet-wimaxasncp.c
index 8e3e781d24..69e328358c 100644
--- a/plugins/wimaxasncp/packet-wimaxasncp.c
+++ b/plugins/wimaxasncp/packet-wimaxasncp.c
@@ -1632,14 +1632,14 @@ static void wimaxasncp_dissect_tlv_value(
             eap_tvb = tvb_new_subset_remaining(tvb, offset);
 
             /* Disable writing to info column while calling eap dissector */
-            save_writable = col_get_writable(pinfo->cinfo);
-            col_set_writable(pinfo->cinfo, FALSE);
+            save_writable = col_get_writable(pinfo->cinfo, -1);
+            col_set_writable(pinfo->cinfo, -1, FALSE);
 
             /* Call the EAP dissector. */
             call_dissector(eap_handle, eap_tvb, pinfo, eap_tree);
 
             /* Restore previous writable state of info column */
-            col_set_writable(pinfo->cinfo, save_writable);
+            col_set_writable(pinfo->cinfo, -1, save_writable);
         }
 
         return;
diff --git a/ui/cli/tap-protocolinfo.c b/ui/cli/tap-protocolinfo.c
index 8227c1b948..23581bc127 100644
--- a/ui/cli/tap-protocolinfo.c
+++ b/ui/cli/tap-protocolinfo.c
@@ -59,7 +59,7 @@ protocolinfo_packet(void *prs, packet_info *pinfo, epan_dissect_t *edt, const vo
 	 * To prevent a crash, we check whether INFO column is writable
 	 * and, if not, we report that error and exit.
 	 */
-	if (!col_get_writable(pinfo->cinfo)) {
+	if (!col_get_writable(pinfo->cinfo, COL_INFO)) {
 		fprintf(stderr, "tshark: the proto,colinfo tap doesn't work if the INFO column isn't being printed.\n");
 		exit(1);
 	}