fix for a bug in bmesh_jekv (and its main caller BM_vert_collapse_faces).

Collapsing an edge could result on 2 edges sharing the same verts, now check for this and 'splice' one edge into another.

4 files changed, 33 insertions, 16 deletions

diff --git a/source/blender/bmesh/intern/bmesh_mods.c b/source/blender/bmesh/intern/bmesh_mods.c
index 471a9f3965f..e512126ce80 100644
--- a/source/blender/bmesh/intern/bmesh_mods.c
+++ b/source/blender/bmesh/intern/bmesh_mods.c
@@ -478,8 +478,8 @@ BMEdge *BM_vert_collapse_faces(BMesh *bm, BMEdge *ke, BMVert *kv, float fac, con
 	/* single face or no faces */
 	/* same as BM_vert_collapse_edge() however we already
 	 * have vars to perform this operation so dont call. */
-	bmesh_jekv(bm, ke, kv);
-	ne = BM_edge_exists(tv, tv2);
+	ne = bmesh_jekv(bm, ke, kv, TRUE);
+	/* ne = BM_edge_exists(tv, tv2); */ /* same as return above */
 
 	return ne;
 }
@@ -512,9 +512,9 @@ BMEdge *BM_vert_collapse_edge(BMesh *bm, BMEdge *ke, BMVert *kv)
 			BMVert *tv2 = BM_edge_other_vert(e2, kv);
 			if (tv2) {
 				/* only action, other calls here only get the edge to return */
-				bmesh_jekv(bm, ke, kv);
+				ne = bmesh_jekv(bm, ke, kv);
 
-				ne = BM_edge_exists(tv, tv2);
+				/* ne = BM_edge_exists(tv, tv2); */ /* same as return above */
 			}
 		}
 	}
diff --git a/source/blender/bmesh/intern/bmesh_newcore.c b/source/blender/bmesh/intern/bmesh_newcore.c
index 2966af9baf8..a03e1512557 100644
--- a/source/blender/bmesh/intern/bmesh_newcore.c
+++ b/source/blender/bmesh/intern/bmesh_newcore.c
@@ -41,6 +41,8 @@
  * TESTING ONLY! */
 // #define USE_DEBUG_INDEX_MEMCHECK
 
+static int bmesh_edge_splice(BMesh *bm, BMEdge *e, BMEdge *etarget);
+
 #ifdef USE_DEBUG_INDEX_MEMCHECK
 #define DEBUG_MEMCHECK_INDEX_INVALIDATE(ele)               \
 	{                                                      \
@@ -1434,9 +1436,9 @@ BMVert *bmesh_semv(BMesh *bm, BMVert *tv, BMEdge *e, BMEdge **re)
  *  these faces.
  *
  *  Returns -
- *	1 for success, 0 for failure.
+ *	The resulting edge, NULL for failure.
  */
-int bmesh_jekv(BMesh *bm, BMEdge *ke, BMVert *kv)
+struct BMEdge *bmesh_jekv(BMesh *bm, BMEdge *ke, BMVert *kv, const short check_edge_double)
 {
 	BMEdge *oe;
 	BMVert *ov, *tv;
@@ -1444,7 +1446,7 @@ int bmesh_jekv(BMesh *bm, BMEdge *ke, BMVert *kv)
 	int len, radlen = 0, halt = 0, i, valence1, valence2, edok;
 
 	if (bmesh_vert_in_edge(ke, kv) == 0) {
-		return FALSE;
+		return NULL;
 	}
 
 	len = bmesh_disk_count(kv);
@@ -1456,13 +1458,19 @@ int bmesh_jekv(BMesh *bm, BMEdge *ke, BMVert *kv)
 		halt = bmesh_verts_in_edge(kv, tv, oe); /* check for double edge */
 		
 		if (halt) {
-			return FALSE;
+			return NULL;
 		}
 		else {
+			BMEdge *e_splice;
+
 			/* For verification later, count valence of ov and t */
 			valence1 = bmesh_disk_count(ov);
 			valence2 = bmesh_disk_count(tv);
-			
+
+			if (check_edge_double) {
+				e_splice = BM_edge_exists(tv, ov);
+			}
+
 			/* remove oe from kv's disk cycl */
 			bmesh_disk_remove_edge(oe, kv);
 			/* relink oe->kv to be oe->t */
@@ -1547,14 +1555,21 @@ int bmesh_jekv(BMesh *bm, BMEdge *ke, BMVert *kv)
 				BM_CHECK_ELEMENT(bm, l->f);
 			}
 
+			if (check_edge_double) {
+				if (e_splice) {
+					/* removes e_splice */
+					bmesh_edge_splice(bm, e_splice, oe);
+				}
+			}
+
 			BM_CHECK_ELEMENT(bm, ov);
 			BM_CHECK_ELEMENT(bm, tv);
 			BM_CHECK_ELEMENT(bm, oe);
 
-			return TRUE;
+			return oe;
 		}
 	}
-	return FALSE;
+	return NULL;
 }
 
 /**
@@ -1718,7 +1733,7 @@ BMFace *bmesh_jfke(BMesh *bm, BMFace *f1, BMFace *f2, BMEdge *e)
  *
  * merges two verts into one (v into vtarget).
  */
-static int bmesh_splicevert(BMesh *bm, BMVert *v, BMVert *vtarget)
+static int bmesh_vert_splice(BMesh *bm, BMVert *v, BMVert *vtarget)
 {
 	BMEdge *e;
 	BMLoop *l;
@@ -1861,7 +1876,7 @@ static int bmesh_cutvert(BMesh *bm, BMVert *v, BMVert ***vout, int *len)
  *
  * edges must already have the same vertices
  */
-static int UNUSED_FUNCTION(bmesh_spliceedge)(BMesh *bm, BMEdge *e, BMEdge *etarget)
+static int bmesh_edge_splice(BMesh *bm, BMEdge *e, BMEdge *etarget)
 {
 	BMLoop *l;
 
@@ -1883,6 +1898,7 @@ static int UNUSED_FUNCTION(bmesh_spliceedge)(BMesh *bm, BMEdge *e, BMEdge *etarg
 	BM_CHECK_ELEMENT(bm, e);
 	BM_CHECK_ELEMENT(bm, etarget);
 
+	/* removes from disks too */
 	BM_edge_kill(bm, e);
 
 	return TRUE;
@@ -1992,7 +2008,7 @@ static BMVert *bmesh_urmv_loop(BMesh *bm, BMLoop *sl)
 
 			/* And then glue the rest back together */
 			for (i = 1; i < len - 1; i++) {
-				bmesh_splicevert(bm, vtar[i], vtar[0]);
+				bmesh_vert_splice(bm, vtar[i], vtar[0]);
 			}
 		}
 	}
diff --git a/source/blender/bmesh/intern/bmesh_structure.h b/source/blender/bmesh/intern/bmesh_structure.h
index 1c00183e03a..a569c98d16d 100644
--- a/source/blender/bmesh/intern/bmesh_structure.h
+++ b/source/blender/bmesh/intern/bmesh_structure.h
@@ -90,7 +90,8 @@ struct BMFace *bmesh_sfme(struct BMesh *bm, struct BMFace *f, struct BMVert *v1,
 #endif
                           BMEdge *example
                           );
-int bmesh_jekv(struct BMesh *bm, struct BMEdge *ke, struct BMVert *kv);
+
+struct BMEdge *bmesh_jekv(struct BMesh *bm, struct BMEdge *ke, struct BMVert *kv, const short check_edge_splice);
 int bmesh_loop_reverse(struct BMesh *bm, struct BMFace *f);
 struct BMFace *bmesh_jfke(struct BMesh *bm, struct BMFace *f1, struct BMFace *f2, struct BMEdge *e);
 
diff --git a/source/blender/bmesh/tools/BME_bevel.c b/source/blender/bmesh/tools/BME_bevel.c
index 134b7f9eb0c..144a0f7ea5e 100644
--- a/source/blender/bmesh/tools/BME_bevel.c
+++ b/source/blender/bmesh/tools/BME_bevel.c
@@ -153,7 +153,7 @@ static int BME_Bevel_Dissolve_Disk(BMesh *bm, BMVert *v)
 
 		e = v->e;
 		elast = bmesh_disk_nextedge(e, v);
-		bmesh_jekv(bm, e, v);
+		bmesh_jekv(bm, e, v, FALSE);
 
 		l1 = elast->l;
 		l2 = l1->radial_next;