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, 7 insertions, 4 deletions

diff --git a/tfshark.c b/tfshark.c
index 0132208e60..c05dbadcdd 100644
--- a/tfshark.c
+++ b/tfshark.c
@@ -793,6 +793,7 @@ main(int argc, char *argv[])
   gchar               *dfilter = NULL;
   dfilter_t           *rfcode = NULL;
   dfilter_t           *dfcode = NULL;
+  gchar               *err_msg;
   e_prefs             *prefs_p;
   int                  log_flags;
   gchar               *output_only = NULL;
@@ -1430,8 +1431,9 @@ main(int argc, char *argv[])
   build_column_format_array(&cfile.cinfo, prefs_p->num_cols, TRUE);
 
   if (rfilter != NULL) {
-    if (!dfilter_compile(rfilter, &rfcode)) {
-      cmdarg_err("%s", dfilter_error_msg);
+    if (!dfilter_compile(rfilter, &rfcode, &err_msg)) {
+      cmdarg_err("%s", err_msg);
+      g_free(err_msg);
       epan_cleanup();
       return 2;
     }
@@ -1439,8 +1441,9 @@ main(int argc, char *argv[])
   cfile.rfcode = rfcode;
 
   if (dfilter != NULL) {
-    if (!dfilter_compile(dfilter, &dfcode)) {
-      cmdarg_err("%s", dfilter_error_msg);
+    if (!dfilter_compile(dfilter, &dfcode, &err_msg)) {
+      cmdarg_err("%s", err_msg);
+      g_free(err_msg);
       epan_cleanup();
       return 2;
     }