Try to fix interface property fetching.

Use g_strdup instead of calculating string lengths manually. Return NULL
for empty strings, otherwise lo0 shows up as ": lo0" instead of
"Loopback: lo0" here.

Change-Id: I143aa5e12c9512b7a9f4729b62b353c13ee3635a
Reviewed-on: https://code.wireshark.org/review/7764
Reviewed-by: Gerald Combs <gerald@wireshark.org>

1 files changed, 6 insertions, 11 deletions

diff --git a/ui/capture_ui_utils.c b/ui/capture_ui_utils.c
index a0f13d1bbd..f94afb6b3a 100644
--- a/ui/capture_ui_utils.c
+++ b/ui/capture_ui_utils.c
@@ -79,21 +79,16 @@ capture_dev_get_if_property(const gchar *pref, const gchar *if_name)
       break;
     }
     closing_parenp = strrchr(if_tokens[i], ')');
-    if (closing_parenp == NULL) {
-      /* No closing parenthesis. Give up. */
+    if (closing_parenp == NULL || closing_parenp <= opening_parenp) {
+      /* No closing parenthesis or invalid input. Give up. */
       break;
     }
     *opening_parenp = '\0'; /* Split {name} from what follows */
+    *closing_parenp = '\0'; /* Terminate {property} */
     if (strcmp(if_tokens[i], if_name) == 0) {
-      /*
-       * Copy everything from opening_parenp + 1 to closing_parenp - 1.
-       * That requires (closing_parenp - 1) - (opening_parenp + 1) + 1
-       * bytes, including the trailing '\0', so that's
-       * (closing_parenp - opening_parenp) - 1.
-       */
-      property = (gchar *)g_malloc(closing_parenp - opening_parenp - 1);
-      memcpy(property, opening_parenp + 1, closing_parenp - opening_parenp - 1);
-      property[closing_parenp - opening_parenp - 1] = '\0';
+      if (strlen(opening_parenp + 1) > 0) {
+        property = g_strdup(opening_parenp + 1);
+      }
       break;
     }
   }