More checks for localtime() and gmtime() returning NULL.

And some comments in the case where we're converting the result of
time() - if your machine's idea of time predates January 1, 1970,
00:00:00 UTC, it'll crash on Windows, but that's not a case where a
*file* can cause the problem due either to a bad file time stamp or bad
time stamps in the file.

Change-Id: I837a438e4b875dd8c4f3ec2137df7a16ee4e9498
Reviewed-on: https://code.wireshark.org/review/18369
Reviewed-by: Guy Harris <guy@alum.mit.edu>

2 files changed, 108 insertions, 78 deletions

diff --git a/ui/cli/tap-iostat.c b/ui/cli/tap-iostat.c
index c23eb63bcb..1ff9b38b00 100644
--- a/ui/cli/tap-iostat.c
+++ b/ui/cli/tap-iostat.c
@@ -1013,60 +1013,78 @@ iostat_draw(void *arg)
         switch (timestamp_get_type()) {
         case TS_ABSOLUTE:
           tm_time = localtime(&the_time);
-          printf("| %02d:%02d:%02d |",
-             tm_time->tm_hour,
-             tm_time->tm_min,
-             tm_time->tm_sec);
+          if (tm_time != NULL) {
+            printf("| %02d:%02d:%02d |",
+               tm_time->tm_hour,
+               tm_time->tm_min,
+               tm_time->tm_sec);
+          } else
+            printf("| XX:XX:XX |");
           break;
 
         case TS_ABSOLUTE_WITH_YMD:
           tm_time = localtime(&the_time);
-          printf("| %04d-%02d-%02d %02d:%02d:%02d |",
-             tm_time->tm_year + 1900,
-             tm_time->tm_mon + 1,
-             tm_time->tm_mday,
-             tm_time->tm_hour,
-             tm_time->tm_min,
-             tm_time->tm_sec);
+          if (tm_time != NULL) {
+            printf("| %04d-%02d-%02d %02d:%02d:%02d |",
+               tm_time->tm_year + 1900,
+               tm_time->tm_mon + 1,
+               tm_time->tm_mday,
+               tm_time->tm_hour,
+               tm_time->tm_min,
+               tm_time->tm_sec);
+          } else
+            printf("| XXXX-XX-XX XX:XX:XX |");
           break;
 
         case TS_ABSOLUTE_WITH_YDOY:
           tm_time = localtime(&the_time);
-          printf("| %04d/%03d %02d:%02d:%02d |",
-             tm_time->tm_year + 1900,
-             tm_time->tm_yday + 1,
-             tm_time->tm_hour,
-             tm_time->tm_min,
-             tm_time->tm_sec);
+          if (tm_time != NULL) {
+            printf("| %04d/%03d %02d:%02d:%02d |",
+               tm_time->tm_year + 1900,
+               tm_time->tm_yday + 1,
+               tm_time->tm_hour,
+               tm_time->tm_min,
+               tm_time->tm_sec);
+          } else
+            printf("| XXXX/XXX XX:XX:XX |");
           break;
 
         case TS_UTC:
           tm_time = gmtime(&the_time);
-          printf("| %02d:%02d:%02d |",
-             tm_time->tm_hour,
-             tm_time->tm_min,
-             tm_time->tm_sec);
+          if (tm_time != NULL) {
+            printf("| %02d:%02d:%02d |",
+               tm_time->tm_hour,
+               tm_time->tm_min,
+               tm_time->tm_sec);
+          } else
+            printf("| XX:XX:XX |");
           break;
 
         case TS_UTC_WITH_YMD:
           tm_time = gmtime(&the_time);
-          printf("| %04d-%02d-%02d %02d:%02d:%02d |",
-             tm_time->tm_year + 1900,
-             tm_time->tm_mon + 1,
-             tm_time->tm_mday,
-             tm_time->tm_hour,
-             tm_time->tm_min,
-             tm_time->tm_sec);
+          if (tm_time != NULL) {
+            printf("| %04d-%02d-%02d %02d:%02d:%02d |",
+               tm_time->tm_year + 1900,
+               tm_time->tm_mon + 1,
+               tm_time->tm_mday,
+               tm_time->tm_hour,
+               tm_time->tm_min,
+               tm_time->tm_sec);
+          } else
+            printf("| XXXX-XX-XX XX:XX:XX |");
           break;
 
         case TS_UTC_WITH_YDOY:
           tm_time = gmtime(&the_time);
-          printf("| %04d/%03d %02d:%02d:%02d |",
-             tm_time->tm_year + 1900,
-             tm_time->tm_yday + 1,
-             tm_time->tm_hour,
-             tm_time->tm_min,
-             tm_time->tm_sec);
+          if (tm_time != NULL) {
+            printf("| %04d/%03d %02d:%02d:%02d |",
+               tm_time->tm_year + 1900,
+               tm_time->tm_yday + 1,
+               tm_time->tm_hour,
+               tm_time->tm_min,
+               tm_time->tm_sec);
+          } else
+            printf("| XXXX/XXX XX:XX:XX |");
           break;
 
         case TS_RELATIVE:
diff --git a/ui/cli/tap-iousers.c b/ui/cli/tap-iousers.c
index 06f02697ac..129b56e580 100644
--- a/ui/cli/tap-iousers.c
+++ b/ui/cli/tap-iousers.c
@@ -140,71 +140,83 @@ iousers_draw(void *arg)
 				switch (timestamp_get_type()) {
 				case TS_ABSOLUTE:
 					tm_time = localtime(&iui->start_abs_time.secs);
-					printf("%02d:%02d:%02d   %12.4f\n",
-						 tm_time->tm_hour,
-						 tm_time->tm_min,
-						 tm_time->tm_sec,
-						 nstime_to_sec(&iui->stop_time) - nstime_to_sec(&iui->start_time));
+					if (tm_time != NULL) {
+						printf("%02d:%02d:%02d",
+							 tm_time->tm_hour,
+							 tm_time->tm_min,
+							 tm_time->tm_sec);
+					} else
+						printf("XX:XX:XX");
 					break;
 				case TS_ABSOLUTE_WITH_YMD:
 					tm_time = localtime(&iui->start_abs_time.secs);
-					printf("%04d-%02d-%02d %02d:%02d:%02d   %12.4f\n",
-						 tm_time->tm_year + 1900,
-						 tm_time->tm_mon + 1,
-						 tm_time->tm_mday,
-						 tm_time->tm_hour,
-						 tm_time->tm_min,
-						 tm_time->tm_sec,
-						 nstime_to_sec(&iui->stop_time) - nstime_to_sec(&iui->start_time));
+					if (tm_time != NULL) {
+						printf("%04d-%02d-%02d %02d:%02d:%02d",
+							 tm_time->tm_year + 1900,
+							 tm_time->tm_mon + 1,
+							 tm_time->tm_mday,
+							 tm_time->tm_hour,
+							 tm_time->tm_min,
+							 tm_time->tm_sec);
+					} else
+						printf("XXXX-XX-XX XX:XX:XX");
 					break;
 				case TS_ABSOLUTE_WITH_YDOY:
 					tm_time = localtime(&iui->start_abs_time.secs);
-					printf("%04d/%03d %02d:%02d:%02d   %12.4f\n",
-						 tm_time->tm_year + 1900,
-						 tm_time->tm_yday + 1,
-						 tm_time->tm_hour,
-						 tm_time->tm_min,
-						 tm_time->tm_sec,
-						 nstime_to_sec(&iui->stop_time) - nstime_to_sec(&iui->start_time));
+					if (tm_time != NULL) {
+						printf("%04d/%03d %02d:%02d:%02d",
+							 tm_time->tm_year + 1900,
+							 tm_time->tm_yday + 1,
+							 tm_time->tm_hour,
+							 tm_time->tm_min,
+							 tm_time->tm_sec);
+					} else
+						printf("XXXX/XXX XX:XX:XX");
 					break;
 				case TS_UTC:
 					tm_time = gmtime(&iui->start_abs_time.secs);
-					printf("%02d:%02d:%02d   %12.4f\n",
-						 tm_time->tm_hour,
-						 tm_time->tm_min,
-						 tm_time->tm_sec,
-						 nstime_to_sec(&iui->stop_time) - nstime_to_sec(&iui->start_time));
+					if (tm_time != NULL) {
+						printf("%02d:%02d:%02d",
+							 tm_time->tm_hour,
+							 tm_time->tm_min,
+							 tm_time->tm_sec);
+					} else
+						printf("XX:XX:XX");
 					break;
 				case TS_UTC_WITH_YMD:
 					tm_time = gmtime(&iui->start_abs_time.secs);
-					printf("%04d-%02d-%02d %02d:%02d:%02d   %12.4f\n",
-						 tm_time->tm_year + 1900,
-						 tm_time->tm_mon + 1,
-						 tm_time->tm_mday,
-						 tm_time->tm_hour,
-						 tm_time->tm_min,
-						 tm_time->tm_sec,
-						 nstime_to_sec(&iui->stop_time) - nstime_to_sec(&iui->start_time));
+					if (tm_time != NULL) {
+						printf("%04d-%02d-%02d %02d:%02d:%02d",
+							 tm_time->tm_year + 1900,
+							 tm_time->tm_mon + 1,
+							 tm_time->tm_mday,
+							 tm_time->tm_hour,
+							 tm_time->tm_min,
+							 tm_time->tm_sec);
+					} else
+						printf("XXXX-XX-XX XX:XX:XX");
 					break;
 				case TS_UTC_WITH_YDOY:
 					tm_time = gmtime(&iui->start_abs_time.secs);
-					printf("%04d/%03d %02d:%02d:%02d   %12.4f\n",
-						 tm_time->tm_year + 1900,
-						 tm_time->tm_yday + 1,
-						 tm_time->tm_hour,
-						 tm_time->tm_min,
-						 tm_time->tm_sec,
-						 nstime_to_sec(&iui->stop_time) - nstime_to_sec(&iui->start_time));
+					if (tm_time != NULL) {
+						printf("%04d/%03d %02d:%02d:%02d",
+							 tm_time->tm_year + 1900,
+							 tm_time->tm_yday + 1,
+							 tm_time->tm_hour,
+							 tm_time->tm_min,
+							 tm_time->tm_sec);
+					} else
+						printf("XXXX/XXX XX:XX:XX");
 					break;
 				case TS_RELATIVE:
 				case TS_NOT_SET:
 				default:
-					printf("%14.9f   %12.4f\n",
-						nstime_to_sec(&iui->start_time),
-						nstime_to_sec(&iui->stop_time) - nstime_to_sec(&iui->start_time)
-					);
+					printf("%14.9f",
+						nstime_to_sec(&iui->start_time));
 					break;
 				}
+				printf("   %12.4f\n",
+					 nstime_to_sec(&iui->stop_time) - nstime_to_sec(&iui->start_time));
 			}
 		}
 		max_frames = last_frames;