Clean up ftype-conversion and dfilter error message string handling.

Have dfilter_compile() take an additional gchar ** argument, pointing to
a gchar * item that, on error, gets set to point to a g_malloc()ed error
string.  That removes one bit of global state from the display filter
parser, and doesn't impose a fixed limit on the error message strings.

Have fvalue_from_string() and fvalue_from_unparsed() take a gchar **
argument, pointer to a gchar * item, rather than an error-reporting
function, and set the gchar * item to point to a g_malloc()ed error
string on an error.

Allow either gchar ** argument to be null; if the argument is null, no
error message is allocated or provided.

Change-Id: Ibd36b8aaa9bf4234aa6efa1e7fb95f7037493b4c
Reviewed-on: https://code.wireshark.org/review/6608
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 4 insertions, 2 deletions

diff --git a/dftest.c b/dftest.c
index 5c28cc6eeb..9945d3632a 100644
--- a/dftest.c
+++ b/dftest.c
@@ -60,6 +60,7 @@ main(int argc, char **argv)
 	int		gpf_open_errno, gpf_read_errno;
 	int		pf_open_errno, pf_read_errno;
 	dfilter_t	*df;
+	gchar		*err_msg;
 
 	/*
 	 * Get credential information for later use.
@@ -144,8 +145,9 @@ main(int argc, char **argv)
 	printf("Filter: \"%s\"\n", text);
 
 	/* Compile it */
-	if (!dfilter_compile(text, &df)) {
-		fprintf(stderr, "dftest: %s\n", dfilter_error_msg);
+	if (!dfilter_compile(text, &df, &err_msg)) {
+		fprintf(stderr, "dftest: %s\n", err_msg);
+		g_free(err_msg);
 		epan_cleanup();
 		exit(2);
 	}