1 files changed, 40 insertions, 23 deletions

diff --git a/epan/dfilter/dfilter.c b/epan/dfilter/dfilter.c
index 8e21d30853..903ec33868 100644
--- a/epan/dfilter/dfilter.c
+++ b/epan/dfilter/dfilter.c
@@ -34,10 +34,6 @@
 
 #define DFILTER_TOKEN_ID_OFFSET	1
 
-/* Global error message space for dfilter_compile errors */
-static gchar dfilter_error_msg_buf[1024];
-const gchar *dfilter_error_msg;	/* NULL when no error resulted */
-
 /* From scanner.c */
 void df_scanner_text(const char *text);
 void    df_scanner_cleanup(void);
@@ -46,24 +42,26 @@ int     df_lex(void);
 /* Holds the singular instance of our Lemon parser object */
 static void*	ParserObj = NULL;
 
+/*
+ * XXX - if we're using a version of Flex that supports reentrant lexical
+ * analyzers, we should put this into the lexical analyzer's state.
+ */
+dfwork_t *global_dfw;
+
 void
-dfilter_fail(const char *format, ...)
+dfilter_fail(dfwork_t *dfw, const char *format, ...)
 {
 	va_list	args;
 
 	/* If we've already reported one error, don't overwite it */
-	if (dfilter_error_msg != NULL)
+	if (dfw->error_message != NULL)
 		return;
 
 	va_start(args, format);
-
-	g_vsnprintf(dfilter_error_msg_buf, sizeof(dfilter_error_msg_buf),
-			format, args);
-	dfilter_error_msg = dfilter_error_msg_buf;
+	dfw->error_message = g_strdup_vprintf(format, args);
 	va_end(args);
 }
 
-
 /* Initialize the dfilter module */
 void
 dfilter_init(void)
@@ -110,7 +108,7 @@ dfilter_new(void)
 
 	df = g_new0(dfilter_t, 1);
 	df->insns = NULL;
-    df->deprecated = NULL;
+	df->deprecated = NULL;
 
 	return df;
 }
@@ -202,11 +200,15 @@ dfwork_free(dfwork_t *dfw)
 		free_insns(dfw->consts);
 	}
 
+	/*
+	 * We don't free the error message string; our caller will return
+	 * it to its caller.
+	 */
 	g_free(dfw);
 }
 
 gboolean
-dfilter_compile(const gchar *text, dfilter_t **dfp)
+dfilter_compile(const gchar *text, dfilter_t **dfp, gchar **err_msg)
 {
 	int		token;
 	dfilter_t	*dfilter;
@@ -216,26 +218,28 @@ dfilter_compile(const gchar *text, dfilter_t **dfp)
 	guint		i;
 	/* XXX, GHashTable */
 	GPtrArray	*deprecated;
-	gchar *temp_error_msg;
 
 	g_assert(dfp);
 
 	if (!text) {
 		*dfp = NULL;
+		if (err_msg != NULL)
+			*err_msg = g_strdup("BUG: NULL text pointer passed to dfilter_compile()");
 		return FALSE;
 	}
 
-	dfilter_error_msg = NULL;
-
-	if ( !( text = dfilter_macro_apply(text, &temp_error_msg) ) ) {
-		/* Move the ep_ allocation up a layer */
-		dfilter_error_msg = ep_strdup(temp_error_msg);
-		wmem_free(NULL, temp_error_msg);
+	if ( !( text = dfilter_macro_apply(text, err_msg) ) ) {
 		return FALSE;
 	}
 
 	dfw = dfwork_new();
 
+	/*
+	 * XXX - if we're using a version of Flex that supports reentrant lexical
+	 * analyzers, we should put this into the lexical analyzer's state.
+	 */
+	global_dfw = dfw;
+
 	df_scanner_text(text);
 
 	deprecated = g_ptr_array_new();
@@ -353,12 +357,18 @@ dfilter_compile(const gchar *text, dfilter_t **dfp)
 		*dfp = dfilter;
 	}
 	/* SUCCESS */
+	global_dfw = NULL;
 	dfwork_free(dfw);
 	wmem_free(NULL, (char*)text);
 	return TRUE;
 
 FAILURE:
 	if (dfw) {
+		if (err_msg != NULL)
+			*err_msg = dfw->error_message;
+		else
+			g_free(dfw->error_message);
+		global_dfw = NULL;
 		dfwork_free(dfw);
 	}
 	for (i = 0; i < deprecated->len; ++i) {
@@ -366,11 +376,18 @@ FAILURE:
 		g_free(depr);
 	}
 	g_ptr_array_free(deprecated, TRUE);
-	dfilter_fail("Unable to parse filter string \"%s\".", text);
-	wmem_free(NULL, (char*)text);
+	if (err_msg != NULL) {
+		/*
+		 * Default error message.
+		 *
+		 * XXX - we should really make sure that this is never the
+		 * case for any error.
+		 */
+		if (*err_msg == NULL)
+			*err_msg = g_strdup_printf("Unable to parse filter string \"%s\".", text);
+	}
 	*dfp = NULL;
 	return FALSE;
-
 }