Fix crash on edge slide when object has got multires modifier

Issue was caused by fix for slide+automerge bug resulted in accessing to freed memory
from multires projection code. Solved by moving multires projection from cleanup callback
to special_aftertrans_update.

Patch by Antony Riakiotakis with some own corrections.

3 files changed, 17 insertions, 10 deletions

diff --git a/source/blender/editors/transform/transform.c b/source/blender/editors/transform/transform.c
index f8782f47ad2..2b2ad563f0a 100644
--- a/source/blender/editors/transform/transform.c
+++ b/source/blender/editors/transform/transform.c
@@ -4783,16 +4783,6 @@ void freeSlideVerts(TransInfo *t)
 	if (!sld)
 		return;
 	
-	/*handle multires reprojection, done
-      on transform completion since it's
-      really slow -joeedh*/
-	if (t->state != TRANS_CANCEL) {
-		projectSVData(t, 1);
-	} else {
-		sld->perc = 0.0;
-		projectSVData(t, 0);
-	}
-
 	freeSlideTempFaces(sld);
 
 	sld->em->bm->ob = t->obedit;
diff --git a/source/blender/editors/transform/transform.h b/source/blender/editors/transform/transform.h
index 545d2348f82..07c90f95840 100644
--- a/source/blender/editors/transform/transform.h
+++ b/source/blender/editors/transform/transform.h
@@ -691,5 +691,6 @@ int getTransformOrientation(const struct bContext *C, float normal[3], float pla
 
 void freeSlideTempFaces(SlideData *sld);
 void freeSlideVerts(TransInfo *t);
+void projectSVData(TransInfo *t, int final);
 
 #endif
diff --git a/source/blender/editors/transform/transform_conversions.c b/source/blender/editors/transform/transform_conversions.c
index 39a89940e17..4de220af959 100644
--- a/source/blender/editors/transform/transform_conversions.c
+++ b/source/blender/editors/transform/transform_conversions.c
@@ -4877,10 +4877,26 @@ void special_aftertrans_update(bContext *C, TransInfo *t)
 				/* we need to delete the temporary faces before automerging */
 				if(t->mode == TFM_EDGE_SLIDE){
 					SlideData *sld = t->customData;
+
+					/* handle multires reprojection, done
+					 * on transform completion since it's
+					 * really slow -joeedh */
+					projectSVData(t, TRUE);
+
+					/* free temporary faces to avoid automerging and deleting
+					 * during cleanup - psy-fi */
 					freeSlideTempFaces(sld);
 				}
 				EDBM_automerge(t->scene, t->obedit, 1);
 			}
+			else {
+				if (t->mode == TFM_EDGE_SLIDE) {
+					SlideData *sld = t->customData;
+
+					sld->perc = 0.0;
+					projectSVData(t, FALSE);
+				}
+			}
 		}
 	}