- bpy.path.abspath(), added optional library argument since any paths from linked datablocks are relative to this, not the blend files path, this saves kludgy path code wherever libraries may be used.

- Image "Edit Externally" operator can now edit relative library images.

also minor edits to navmesh.

source/blender/blenkernel/intern/DerivedMesh.c

@@ -64,6 +64,7 @@
 
 #ifdef WITH_GAMEENGINE
 #include "BKE_navmesh_conversion.h"
+static DerivedMesh *navmesh_dm_createNavMeshForVisualization(DerivedMesh *dm);
 #endif
 
 #include "BLO_sys_types.h" // for intptr_t support
@@ -77,8 +78,6 @@
 
 extern GLubyte stipple_quarttone[128]; /* glutil.c, bad level data */
 
-static DerivedMesh *navmesh_dm_createNavMeshForVisualization(DerivedMesh *dm);
-
 ///////////////////////////////////
 ///////////////////////////////////
 

source/blender/editors/mesh/mesh_navmesh.c

@@ -459,12 +459,14 @@ static int create_navmesh_exec(bContext *C, wmOperator *op)
 
 		MEM_freeN(verts);
 		MEM_freeN(tris);
+
+		return OPERATOR_FINISHED;
 	}
 	else {
 		BKE_report(op->reports, RPT_ERROR, "No mesh objects found");
-	}
 
-	return OPERATOR_FINISHED;
+		return OPERATOR_CANCELLED;
+	}
 }
 
 void MESH_OT_navmesh_make(wmOperatorType *ot)