Fix for weight painting errors, as reported by Bassam.

- Undo/Redo didn't work
- Crash on using weightpaint with Armature-modifier (instead of parent).

Note: checking if an object is being deformed cannot be simply done with
checking for a parent anymore... for this a call in modifier.c has been
added; modifiers_isDeformedByArmature(Object *). It even returns the
Armature object pointer.

source/blender/blenkernel/BKE_modifier.h

@@ -201,7 +201,7 @@ void			modifiers_clearErrors		(struct Object *ob);
 int				modifiers_getCageIndex		(struct Object *ob, int *lastPossibleCageIndex_r);
 
 int				modifiers_isSoftbodyEnabled	(struct Object *ob);
-int				modifiers_isDeformedByArmature(struct Object *ob, struct Object *armOb);
+struct Object*	modifiers_isDeformedByArmature(struct Object *ob);
 
 ModifierData*	modifiers_getVirtualModifierList	(struct Object *ob);
 

source/blender/blenkernel/intern/armature.c

@@ -728,8 +728,10 @@ void armature_deform_verts(Object *armOb, Object *target, float (*vertexCos)[3],
 				pchan = defnrToPC[dvert->dw[j].def_nr];
 				if (pchan) {
 					float weight= dvert->dw[j].weight;
-					if(pchan->bone->flag & BONE_MULT_VG_ENV) {
-						Bone *bone= pchan->bone;
+					Bone *bone= pchan->bone;
+					
+					if(bone && bone->flag & BONE_MULT_VG_ENV) {
+						
 						weight*= distfactor_to_bone(co, bone->arm_head, bone->arm_tail, bone->rad_head, bone->rad_tail, bone->dist);
 					}
 					pchan_bone_deform(pchan, weight, vec, co, &contrib);

source/blender/blenkernel/intern/modifier.c

@@ -1494,18 +1494,20 @@ ModifierData *modifiers_getVirtualModifierList(Object *ob)
 	return ob->modifiers.first;
 }
 
-int modifiers_isDeformedByArmature(Object *ob, Object *armOb)
+Object *modifiers_isDeformedByArmature(Object *ob)
 {
 	ModifierData *md = modifiers_getVirtualModifierList(ob);
 
 	for (; md; md=md->next) {
 		if (md->type==eModifierType_Armature) {
 			ArmatureModifierData *amd = (ArmatureModifierData*) md;
-
-			if (amd->object==armOb)
-				return 1;
+			return amd->object;
 		}
 	}
+	
+	if(ob->parent && ob->parent->type==OB_ARMATURE)
+		if(ob->partype==PARSKEL)
+			return ob->parent;
 
-	return 0;
+	return NULL;
 }

source/blender/src/buttons_object.c

@@ -685,7 +685,7 @@ static void draw_constraint (uiBlock *block, ListBase *list, bConstraint *con, s
 					strcpy (data->subtarget, "");
 				uiBlockEndAlign(block);
 
-				but=uiDefButBitI(block, TOG, 1, B_CONSTRAINT_TEST, "Sticky", *xco, *yco-24, 54, 18, &data->sticky, 0, 24, 0, 0, "Immobilize object while constrained");
+				but=uiDefButBitS(block, TOG, 1, B_CONSTRAINT_TEST, "Sticky", *xco, *yco-24, 54, 18, &data->sticky, 0, 24, 0, 0, "Immobilize object while constrained");
 				
 				uiDefBut(block, LABEL, B_CONSTRAINT_TEST, "Max/Min:", *xco-8, *yco-64, 54, 18, NULL, 0.0, 0.0, 0.0, 0.0, ""); 
 

source/blender/src/editarmature.c

@@ -2400,7 +2400,7 @@ static void constraint_bone_name_fix(Object *ob, ListBase *conlist, char *oldnam
 /* seems messy, but thats what you get with not using pointers but channel names :) */
 void armature_bone_rename(bArmature *arm, char *oldnamep, char *newnamep)
 {
-	Object *ob;
+	Object *ob, *modob;
 	char newname[MAXBONENAME];
 	char oldname[MAXBONENAME];
 	
@@ -2481,13 +2481,15 @@ void armature_bone_rename(bArmature *arm, char *oldnamep, char *newnamep)
 					if (!strcmp(ob->parsubstr, oldname))
 						BLI_strncpy(ob->parsubstr, newname, MAXBONENAME);
 				}
-				else if(ob->partype==PARSKEL) {
-					bDeformGroup *dg;
-					/* bone name in defgroup */
-					for (dg=ob->defbase.first; dg; dg=dg->next) {
-						if(!strcmp(dg->name, oldname))
-						   BLI_strncpy(dg->name, newname, MAXBONENAME);
-					}
+			}
+			/* or is there an armature deforming object */
+			modob = modifiers_isDeformedByArmature(ob);
+			if(modob) {
+				bDeformGroup *dg;
+				/* bone name in defgroup */
+				for (dg=ob->defbase.first; dg; dg=dg->next) {
+					if(!strcmp(dg->name, oldname))
+					   BLI_strncpy(dg->name, newname, MAXBONENAME);
 				}
 			}
 		}

source/blender/src/editdeform.c

@@ -109,7 +109,7 @@ the specified defweight group */
 	int	i;
 	MDeformWeight *newdw;
 
-	if (!dv)
+	if (!dv || defgroup<0)
 		return NULL;
 
 	for (i=0; i<dv->totweight; i++){

source/blender/src/vpaint.c

@@ -55,6 +55,7 @@
 #include "DNA_armature_types.h"
 #include "DNA_mesh_types.h"
 #include "DNA_meshdata_types.h"
+#include "DNA_modifier_types.h"
 #include "DNA_object_types.h"
 #include "DNA_object_force.h"
 #include "DNA_screen_types.h"
@@ -68,6 +69,7 @@
 #include "BKE_displist.h"
 #include "BKE_global.h"
 #include "BKE_mesh.h"
+#include "BKE_modifier.h"
 #include "BKE_object.h"
 #include "BKE_utildefines.h"
 
@@ -734,7 +736,8 @@ void wpaint_undo (void)
 	/* now free previous mesh dverts */
 	free_dverts(swapbuf, me->totvert);
 
-	DAG_object_flush_update(G.scene, ob->parent, OB_RECALC_DATA);
+	DAG_object_flush_update(G.scene, ob, OB_RECALC_DATA);
+	DAG_object_flush_update(G.scene, modifiers_isDeformedByArmature(ob), OB_RECALC_DATA);
 	scrarea_do_windraw(curarea);
 	
 }
@@ -911,11 +914,13 @@ void weight_paint(void)
 	/* if nothing was added yet, we make dverts and a vertex deform group */
 	if (!me->dvert)
 		create_dverts(me);
+	
 	/* this happens on a Bone select, when no vgroup existed yet */
 	if(ob->actdef==0) {
-		if(ob->parent && (ob->parent->flag & OB_POSEMODE)) {
+		Object *modob;
+		if(modob = modifiers_isDeformedByArmature(ob)) {
 			bPoseChannel *pchan;
-			for(pchan= ob->parent->pose->chanbase.first; pchan; pchan= pchan->next)
+			for(pchan= modob->pose->chanbase.first; pchan; pchan= pchan->next)
 				if(pchan->bone->flag & SELECT)
 					break;
 			if(pchan) {