fix potential null pointer deref

(bzr r10702)

1 files changed, 14 insertions, 12 deletions

diff --git a/src/extension/effect.cpp b/src/extension/effect.cpp
index b42caca06..4f87e98cd 100644
--- a/src/extension/effect.cpp
+++ b/src/extension/effect.cpp
@@ -296,18 +296,20 @@ Effect::effect (Inkscape::UI::View::View * doc)
 void
 Effect::set_last_effect (Effect * in_effect)
 {
-    gchar const * verb_id = in_effect->get_verb()->get_id();
-    gchar const * help_id_prefix = "org.inkscape.help.";
-
-    // We don't want these "effects" to register as the last effect,
-    // this wouldn't be helpful to the user who selects a real effect,
-    // then goes to the help file (implemented as an effect), then goes
-    // back to the effect, only to see it written over by the help file
-    // selection.
-
-    // This snippet should fix this bug:
-    // https://bugs.launchpad.net/inkscape/+bug/600671
-    if (strncmp(verb_id, help_id_prefix, strlen(help_id_prefix)) == 0) return;
+    if (in_effect) {
+        gchar const * verb_id = in_effect->get_verb()->get_id();
+        gchar const * help_id_prefix = "org.inkscape.help.";
+
+        // We don't want these "effects" to register as the last effect,
+        // this wouldn't be helpful to the user who selects a real effect,
+        // then goes to the help file (implemented as an effect), then goes
+        // back to the effect, only to see it written over by the help file
+        // selection.
+
+        // This snippet should fix this bug:
+        // https://bugs.launchpad.net/inkscape/+bug/600671
+        if (strncmp(verb_id, help_id_prefix, strlen(help_id_prefix)) == 0) return;
+    }
 
     if (in_effect == NULL) {
         Inkscape::Verb::get(SP_VERB_EFFECT_LAST)->sensitive(NULL, false);