Fix LP bug #622350: Discard events when desktop->event_context has not been set, instead of crashing.

(bzr r9728)

2 files changed, 22 insertions, 9 deletions

diff --git a/src/desktop.cpp b/src/desktop.cpp
index a93fb6a4a..1fdad010f 100644
--- a/src/desktop.cpp
+++ b/src/desktop.cpp
@@ -636,9 +636,15 @@ SPDesktop::set_event_context (GtkType type, const gchar *config)
         event_context = next;
     }
 
+    // The event_context will be null. This means that it will be impossible
+    // to process any event invoked by the lines below. See for example bug
+    // LP #622350. Cutting and undoing again in the node tool resets the event
+    // context to the node tool. In this bug the line bellow invokes GDK_LEAVE_NOTIFY
+    // events which cannot be handled and must be discarded.
     ec = sp_event_context_new (type, this, config, SP_EVENT_CONTEXT_STATIC);
     ec->next = event_context;
     event_context = ec;
+    // Now the event_context has been set again and we can process all events again
     sp_event_context_activate (ec);
     _event_context_changed_signal.emit (this, ec);
 }
@@ -1367,7 +1373,7 @@ SPDesktop::emitToolSubselectionChanged(gpointer data)
 void
 SPDesktop::updateNow()
 {
-  sp_canvas_update_now(canvas);
+    sp_canvas_update_now(canvas);
 }
 
 void
diff --git a/src/event-context.cpp b/src/event-context.cpp
index 6184fb4c7..5d60379c8 100644
--- a/src/event-context.cpp
+++ b/src/event-context.cpp
@@ -937,8 +937,12 @@ gint sp_event_context_root_handler(SPEventContext * event_context,
 }
 
 gint sp_event_context_virtual_root_handler(SPEventContext * event_context, GdkEvent * event) {
-    gint ret = ((SPEventContextClass *) G_OBJECT_GET_CLASS(event_context))->root_handler(event_context, event);
-    set_event_location(event_context->desktop, event);
+    gint ret = false;
+    if (event_context) {    // If no event-context is available then do nothing, otherwise Inkscape would crash
+                            // (see the comment in SPDesktop::set_event_context, and bug LP #622350)
+        ret = ((SPEventContextClass *) G_OBJECT_GET_CLASS(event_context))->root_handler(event_context, event);
+        set_event_location(event_context->desktop, event);
+    }
     return ret;
 }
 
@@ -972,12 +976,15 @@ gint sp_event_context_item_handler(SPEventContext * event_context,
 }
 
 gint sp_event_context_virtual_item_handler(SPEventContext * event_context, SPItem * item, GdkEvent * event) {
-    gint ret = ((SPEventContextClass *) G_OBJECT_GET_CLASS(event_context))->item_handler(event_context, item, event);
-
-    if (!ret) {
-        ret = sp_event_context_virtual_root_handler(event_context, event);
-    } else {
-        set_event_location(event_context->desktop, event);
+    gint ret = false;
+    if (event_context) {    // If no event-context is available then do nothing, otherwise Inkscape would crash
+                            // (see the comment in SPDesktop::set_event_context, and bug LP #622350)
+        ret = ((SPEventContextClass *) G_OBJECT_GET_CLASS(event_context))->item_handler(event_context, item, event);
+        if (!ret) {
+            ret = sp_event_context_virtual_root_handler(event_context, event);
+        } else {
+            set_event_location(event_context->desktop, event);
+        }
     }
 
     return ret;