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, 8 insertions, 5 deletions

diff --git a/ui/gtk/main.c b/ui/gtk/main.c
index f5b6028a98..224491a1f1 100644
--- a/ui/gtk/main.c
+++ b/ui/gtk/main.c
@@ -2163,6 +2163,7 @@ main(int argc, char *argv[])
     gint                 pl_size = 280, tv_size = 95, bv_size = 75;
     gchar               *rc_file, *cf_name = NULL, *rfilter = NULL, *dfilter = NULL, *jfilter = NULL;
     dfilter_t           *rfcode = NULL;
+    gchar               *err_msg;
     gboolean             rfilter_parse_failed = FALSE;
     e_prefs             *prefs_p;
     char                 badopt;
@@ -3082,8 +3083,9 @@ main(int argc, char *argv[])
         show_main_window(TRUE);
         check_and_warn_user_startup(cf_name);
         if (rfilter != NULL) {
-            if (!dfilter_compile(rfilter, &rfcode)) {
-                bad_dfilter_alert_box(top_level, rfilter);
+            if (!dfilter_compile(rfilter, &rfcode, &err_msg)) {
+                bad_dfilter_alert_box(top_level, rfilter, err_msg);
+                g_free(err_msg);
                 rfilter_parse_failed = TRUE;
             }
         }
@@ -3121,8 +3123,9 @@ main(int argc, char *argv[])
                             cf_goto_frame(&cfile, go_to_packet);
                         } else if (jfilter != NULL) {
                             /* try to compile given filter */
-                            if (!dfilter_compile(jfilter, &jump_to_filter)) {
-                                bad_dfilter_alert_box(top_level, jfilter);
+                            if (!dfilter_compile(jfilter, &jump_to_filter, &err_msg)) {
+                                bad_dfilter_alert_box(top_level, jfilter, err_msg);
+                                g_free(err_msg);
                             } else {
                             /* Filter ok, jump to the first packet matching the filter
                                conditions. Default search direction is forward, but if
@@ -3859,7 +3862,7 @@ main_fields_changed (void)
     if (cfile.dfilter) {
         /* Check if filter is still valid */
         dfilter_t *dfp = NULL;
-        if (!dfilter_compile(cfile.dfilter, &dfp)) {
+        if (!dfilter_compile(cfile.dfilter, &dfp, NULL)) {
             /* Not valid.  Enable 'Apply' button and remove dfilter. */
             g_signal_emit_by_name(G_OBJECT(main_display_filter_widget), "changed");
             g_free(cfile.dfilter);