Bugfix [#34836] Crash when driver variable has path == 'data'

Most of the places which relied on RNA_path_resolve() did so believing that if
it returned true, that it had found a valid property, and that the returned
pointer+property combination would be what the path referred to. However, it
turns out that if the property at the end of the path turns out to be a
"pointer" property (e.g. "data" for Object.data), this would automatically
become the pointer part, while the prop part would be set to null. Hence, if a
user accidentally (or otherwise) specifies a path for the single-property driver
variable type like this, then Blender would crash.

This commit introduces two convenience functions - RNA_path_resolve_property()
and RNA_path_resolve_property_full() - which mirror/wrap the existing
RNA_path_resolve() functions. The only difference though is that these include a
check to ensure that what was found from resolving the path was in fact a
property (they only return true iff this is the case), and make it explicitly
clear in the name that this is what they will do so that there's no further
confusion. It is possible to do without these wrapper functions by doing these
checks inline, but the few cases that had been patched already were pretty
hideous looking specimens. Using these just make it clearer and simpler for all.

I've also beefed up the docs on these a bit, and changed these to using bools.

15 files changed, 66 insertions, 31 deletions

diff --git a/source/blender/blenkernel/intern/anim_sys.c b/source/blender/blenkernel/intern/anim_sys.c
index 9cdb35586ce..48d83652f56 100644
--- a/source/blender/blenkernel/intern/anim_sys.c
+++ b/source/blender/blenkernel/intern/anim_sys.c
@@ -550,7 +550,7 @@ void BKE_animdata_separate_by_basepath(ID *srcID, ID *dstID, ListBase *basepaths
 /* Path Validation -------------------------------------------- */
 
 /* Check if a given RNA Path is valid, by tracing it from the given ID, and seeing if we can resolve it */
-static short check_rna_path_is_valid(ID *owner_id, const char *path)
+static bool check_rna_path_is_valid(ID *owner_id, const char *path)
 {
 	PointerRNA id_ptr, ptr;
 	PropertyRNA *prop = NULL;
@@ -559,7 +559,7 @@ static short check_rna_path_is_valid(ID *owner_id, const char *path)
 	RNA_id_pointer_create(owner_id, &id_ptr);
 	
 	/* try to resolve */
-	return RNA_path_resolve(&id_ptr, path, &ptr, &prop); 
+	return RNA_path_resolve_property(&id_ptr, path, &ptr, &prop); 
 }
 
 /* Check if some given RNA Path needs fixing - free the given path and set a new one as appropriate 
@@ -1164,7 +1164,7 @@ static short animsys_write_rna_setting(PointerRNA *ptr, char *path, int array_in
 	//printf("%p %s %i %f\n", ptr, path, array_index, value);
 	
 	/* get property to write to */
-	if (RNA_path_resolve(ptr, path, &new_ptr, &prop)) {
+	if (RNA_path_resolve_property(ptr, path, &new_ptr, &prop)) {
 		/* set value - only for animatable numerical values */
 		if (RNA_property_animateable(&new_ptr, prop)) {
 			int array_len = RNA_property_array_length(&new_ptr, prop);
@@ -1650,7 +1650,7 @@ static NlaEvalChannel *nlaevalchan_verify(PointerRNA *ptr, ListBase *channels, N
 	/* free_path = */ /* UNUSED */ animsys_remap_path(strip->remap, fcu->rna_path, &path);
 	
 	/* a valid property must be available, and it must be animatable */
-	if (RNA_path_resolve(ptr, path, &new_ptr, &prop) == 0) {
+	if (RNA_path_resolve_property(ptr, path, &new_ptr, &prop) == false) {
 		if (G.debug & G_DEBUG) printf("NLA Strip Eval: Cannot resolve path\n");
 		return NULL;
 	}
diff --git a/source/blender/blenkernel/intern/fcurve.c b/source/blender/blenkernel/intern/fcurve.c
index 3141d52e22a..c86ee11985a 100644
--- a/source/blender/blenkernel/intern/fcurve.c
+++ b/source/blender/blenkernel/intern/fcurve.c
@@ -1040,7 +1040,7 @@ static float dtar_get_prop_val(ChannelDriver *driver, DriverTarget *dtar)
 	RNA_id_pointer_create(id, &id_ptr);
 	
 	/* get property to read from, and get value as appropriate */
-	if (RNA_path_resolve_full(&id_ptr, dtar->rna_path, &ptr, &prop, &index)) {
+	if (RNA_path_resolve_property_full(&id_ptr, dtar->rna_path, &ptr, &prop, &index)) {
 		if (RNA_property_array_check(prop)) {
 			/* array */
 			if ((index >= 0) && (index < RNA_property_array_length(&ptr, prop))) {
diff --git a/source/blender/editors/animation/anim_channels_defines.c b/source/blender/editors/animation/anim_channels_defines.c
index bd580ab590f..430e7f719b9 100644
--- a/source/blender/editors/animation/anim_channels_defines.c
+++ b/source/blender/editors/animation/anim_channels_defines.c
@@ -3280,7 +3280,7 @@ static void achannel_setting_slider_cb(bContext *C, void *id_poin, void *fcu_poi
 	RNA_id_pointer_create(id, &id_ptr);
 	
 	/* try to resolve the path stored in the F-Curve */
-	if (RNA_path_resolve(&id_ptr, fcu->rna_path, &ptr, &prop)) {
+	if (RNA_path_resolve_property(&id_ptr, fcu->rna_path, &ptr, &prop)) {
 		/* set the special 'replace' flag if on a keyframe */
 		if (fcurve_frame_has_keyframe(fcu, cfra, 0))
 			flag |= INSERTKEY_REPLACE;
@@ -3318,7 +3318,7 @@ static void achannel_setting_slider_shapekey_cb(bContext *C, void *key_poin, voi
 	RNA_id_pointer_create((ID *)key, &id_ptr);
 	
 	/* try to resolve the path stored in the F-Curve */
-	if (RNA_path_resolve(&id_ptr, rna_path, &ptr, &prop)) {
+	if (RNA_path_resolve_property(&id_ptr, rna_path, &ptr, &prop)) {
 		/* find or create new F-Curve */
 		// XXX is the group name for this ok?
 		bAction *act = verify_adt_action((ID *)key, 1);
@@ -3615,7 +3615,7 @@ void ANIM_channel_draw_widgets(bContext *C, bAnimContext *ac, bAnimListElem *ale
 					RNA_id_pointer_create(ale->id, &id_ptr);
 					
 					/* try to resolve the path */
-					if (RNA_path_resolve(&id_ptr, rna_path, &ptr, &prop)) {
+					if (RNA_path_resolve_property(&id_ptr, rna_path, &ptr, &prop)) {
 						uiBut *but;
 						
 						/* create the slider button, and assign relevant callback to ensure keyframes are inserted... */
diff --git a/source/blender/editors/animation/anim_deps.c b/source/blender/editors/animation/anim_deps.c
index 98071fafc1e..618c1b04a71 100644
--- a/source/blender/editors/animation/anim_deps.c
+++ b/source/blender/editors/animation/anim_deps.c
@@ -87,7 +87,7 @@ void ANIM_list_elem_update(Scene *scene, bAnimListElem *ale)
 		
 		RNA_id_pointer_create(id, &id_ptr);
 			
-		if (RNA_path_resolve(&id_ptr, fcu->rna_path, &ptr, &prop))
+		if (RNA_path_resolve_property(&id_ptr, fcu->rna_path, &ptr, &prop))
 			RNA_property_update_main(G.main, scene, &ptr, prop);
 	}
 	else {
diff --git a/source/blender/editors/animation/anim_draw.c b/source/blender/editors/animation/anim_draw.c
index eb1f5ef1043..bd4c2347815 100644
--- a/source/blender/editors/animation/anim_draw.c
+++ b/source/blender/editors/animation/anim_draw.c
@@ -373,7 +373,7 @@ float ANIM_unit_mapping_get_factor(Scene *scene, ID *id, FCurve *fcu, short rest
 		
 		/* get RNA property that F-Curve affects */
 		RNA_id_pointer_create(id, &id_ptr);
-		if (RNA_path_resolve(&id_ptr, fcu->rna_path, &ptr, &prop)) {
+		if (RNA_path_resolve_property(&id_ptr, fcu->rna_path, &ptr, &prop)) {
 			/* rotations: radians <-> degrees? */
 			if (RNA_SUBTYPE_UNIT(RNA_property_subtype(prop)) == PROP_UNIT_ROTATION) {
 				/* if the radians flag is not set, default to using degrees which need conversions */
diff --git a/source/blender/editors/animation/anim_ipo_utils.c b/source/blender/editors/animation/anim_ipo_utils.c
index 2352cad0cbc..21941c7ed62 100644
--- a/source/blender/editors/animation/anim_ipo_utils.c
+++ b/source/blender/editors/animation/anim_ipo_utils.c
@@ -79,7 +79,7 @@ int getname_anim_fcurve(char *name, ID *id, FCurve *fcu)
 		RNA_id_pointer_create(id, &id_ptr);
 		
 		/* try to resolve the path */
-		if (RNA_path_resolve(&id_ptr, fcu->rna_path, &ptr, &prop)) {
+		if (RNA_path_resolve_property(&id_ptr, fcu->rna_path, &ptr, &prop)) {
 			const char *structname = NULL, *propname = NULL;
 			char arrayindbuf[16];
 			const char *arrayname = NULL;
diff --git a/source/blender/editors/animation/drivers.c b/source/blender/editors/animation/drivers.c
index cd5e873f40d..d9965ebdcac 100644
--- a/source/blender/editors/animation/drivers.c
+++ b/source/blender/editors/animation/drivers.c
@@ -145,7 +145,7 @@ short ANIM_add_driver(ReportList *reports, ID *id, const char rna_path[], int ar
 	
 	/* validate pointer first - exit if failure */
 	RNA_id_pointer_create(id, &id_ptr);
-	if ((RNA_path_resolve(&id_ptr, rna_path, &ptr, &prop) == 0) || (prop == NULL)) {
+	if (RNA_path_resolve_property(&id_ptr, rna_path, &ptr, &prop) == false) {
 		BKE_reportf(reports, RPT_ERROR, 
 		            "Could not add driver, as RNA path is invalid for the given ID (ID = %s, path = %s)",
 		            id->name, rna_path);
@@ -308,7 +308,7 @@ short ANIM_copy_driver(ReportList *reports, ID *id, const char rna_path[], int a
 	
 	/* validate pointer first - exit if failure */
 	RNA_id_pointer_create(id, &id_ptr);
-	if ((RNA_path_resolve(&id_ptr, rna_path, &ptr, &prop) == 0) || (prop == NULL)) {
+	if (RNA_path_resolve_property(&id_ptr, rna_path, &ptr, &prop) == false) {
 		BKE_reportf(reports, RPT_ERROR,
 		            "Could not find driver to copy, as RNA path is invalid for the given ID (ID = %s, path = %s)",
 		            id->name, rna_path);
@@ -355,7 +355,7 @@ short ANIM_paste_driver(ReportList *reports, ID *id, const char rna_path[], int
 	
 	/* validate pointer first - exit if failure */
 	RNA_id_pointer_create(id, &id_ptr);
-	if ((RNA_path_resolve(&id_ptr, rna_path, &ptr, &prop) == 0) || (prop == NULL)) {
+	if (RNA_path_resolve_property(&id_ptr, rna_path, &ptr, &prop) == false) {
 		BKE_reportf(reports, RPT_ERROR,
 		            "Could not paste driver, as RNA path is invalid for the given ID (ID = %s, path = %s)",
 		            id->name, rna_path);
diff --git a/source/blender/editors/animation/keyframing.c b/source/blender/editors/animation/keyframing.c
index bc20311f773..d1df93f49f5 100644
--- a/source/blender/editors/animation/keyframing.c
+++ b/source/blender/editors/animation/keyframing.c
@@ -810,7 +810,7 @@ short insert_keyframe_direct(ReportList *reports, PointerRNA ptr, PropertyRNA *p
 		PointerRNA tmp_ptr;
 		
 		/* try to get property we should be affecting */
-		if ((RNA_path_resolve(&ptr, fcu->rna_path, &tmp_ptr, &prop) == 0) || (prop == NULL)) {
+		if (RNA_path_resolve_property(&ptr, fcu->rna_path, &tmp_ptr, &prop) == false) {
 			/* property not found... */
 			const char *idname = (ptr.id.data) ? ((ID *)ptr.id.data)->name : TIP_("<No ID pointer>");
 			
@@ -920,7 +920,7 @@ short insert_keyframe(ReportList *reports, ID *id, bAction *act, const char grou
 	}
 	
 	RNA_id_pointer_create(id, &id_ptr);
-	if ((RNA_path_resolve(&id_ptr, rna_path, &ptr, &prop) == 0) || (prop == NULL)) {
+	if (RNA_path_resolve_property(&id_ptr, rna_path, &ptr, &prop) == false) {
 		BKE_reportf(reports, RPT_ERROR,
 		            "Could not insert keyframe, as RNA path is invalid for the given ID (ID = %s, path = %s)",
 		            (id) ? id->name : TIP_("<Missing ID block>"), rna_path);
@@ -1012,7 +1012,7 @@ short delete_keyframe(ReportList *reports, ID *id, bAction *act, const char grou
 	
 	/* validate pointer first - exit if failure */
 	RNA_id_pointer_create(id, &id_ptr);
-	if ((RNA_path_resolve(&id_ptr, rna_path, &ptr, &prop) == 0) || (prop == NULL)) {
+	if (RNA_path_resolve_property(&id_ptr, rna_path, &ptr, &prop) == false) {
 		BKE_reportf(reports, RPT_ERROR,
 		            "Could not delete keyframe, as RNA path is invalid for the given ID (ID = %s, path = %s)",
 		            id->name, rna_path);
@@ -1113,7 +1113,7 @@ static short clear_keyframe(ReportList *reports, ID *id, bAction *act, const cha
 
 	/* validate pointer first - exit if failure */
 	RNA_id_pointer_create(id, &id_ptr);
-	if ((RNA_path_resolve(&id_ptr, rna_path, &ptr, &prop) == 0) || (prop == NULL)) {
+	if (RNA_path_resolve_property(&id_ptr, rna_path, &ptr, &prop) == false) {
 		BKE_reportf(reports, RPT_ERROR,
 		            "Could not clear keyframe, as RNA path is invalid for the given ID (ID = %s, path = %s)",
 		            id->name, rna_path);
diff --git a/source/blender/editors/animation/keyingsets.c b/source/blender/editors/animation/keyingsets.c
index ad09fcb5966..07825f59c2f 100644
--- a/source/blender/editors/animation/keyingsets.c
+++ b/source/blender/editors/animation/keyingsets.c
@@ -977,7 +977,7 @@ int ANIM_apply_keyingset(bContext *C, ListBase *dsources, bAction *act, KeyingSe
 			PropertyRNA *prop;
 			
 			RNA_id_pointer_create(ksp->id, &id_ptr);
-			if (RNA_path_resolve(&id_ptr, ksp->rna_path, &ptr, &prop) && prop)
+			if (RNA_path_resolve_property(&id_ptr, ksp->rna_path, &ptr, &prop))
 				arraylen = RNA_property_array_length(&ptr, prop);
 		}
 		
diff --git a/source/blender/editors/armature/pose_slide.c b/source/blender/editors/armature/pose_slide.c
index ac01cbb5f4a..0ff0e0d498c 100644
--- a/source/blender/editors/armature/pose_slide.c
+++ b/source/blender/editors/armature/pose_slide.c
@@ -1027,7 +1027,7 @@ static short pose_propagate_get_refVal(Object *ob, FCurve *fcu, float *value)
 	RNA_id_pointer_create(&ob->id, &id_ptr);
 	
 	/* resolve the property... */
-	if (RNA_path_resolve(&id_ptr, fcu->rna_path, &ptr, &prop)) {
+	if (RNA_path_resolve_property(&id_ptr, fcu->rna_path, &ptr, &prop)) {
 		if (RNA_property_array_check(prop)) {
 			/* array */
 			if (fcu->array_index < RNA_property_array_length(&ptr, prop)) {
diff --git a/source/blender/editors/interface/interface_ops.c b/source/blender/editors/interface/interface_ops.c
index 52a26f4f528..e4b76cb0399 100644
--- a/source/blender/editors/interface/interface_ops.c
+++ b/source/blender/editors/interface/interface_ops.c
@@ -551,7 +551,7 @@ static int copy_to_selected_button_poll(bContext *C)
 					if (use_path) {
 						lprop = NULL;
 						RNA_id_pointer_create(link->ptr.id.data, &idptr);
-						RNA_path_resolve(&idptr, path, &lptr, &lprop);
+						RNA_path_resolve_property(&idptr, path, &lptr, &lprop);
 					}
 					else {
 						lptr = link->ptr;
@@ -601,7 +601,7 @@ static int copy_to_selected_button_exec(bContext *C, wmOperator *op)
 					if (use_path) {
 						lprop = NULL;
 						RNA_id_pointer_create(link->ptr.id.data, &idptr);
-						RNA_path_resolve(&idptr, path, &lptr, &lprop);
+						RNA_path_resolve_property(&idptr, path, &lptr, &lprop);
 					}
 					else {
 						lptr = link->ptr;
diff --git a/source/blender/editors/space_graph/graph_buttons.c b/source/blender/editors/space_graph/graph_buttons.c
index f7ec8e8682d..d62ab2850b4 100644
--- a/source/blender/editors/space_graph/graph_buttons.c
+++ b/source/blender/editors/space_graph/graph_buttons.c
@@ -296,7 +296,7 @@ static void graph_panel_key_properties(const bContext *C, Panel *pa)
 		
 		/* get property that F-Curve affects, for some unit-conversion magic */
 		RNA_id_pointer_create(ale->id, &id_ptr);
-		if (RNA_path_resolve(&id_ptr, fcu->rna_path, &fcu_prop_ptr, &fcu_prop) && fcu_prop) {
+		if (RNA_path_resolve_property(&id_ptr, fcu->rna_path, &fcu_prop_ptr, &fcu_prop)) {
 			/* determine the unit for this property */
 			unit = RNA_SUBTYPE_UNIT(RNA_property_subtype(fcu_prop));
 		}
diff --git a/source/blender/makesrna/RNA_access.h b/source/blender/makesrna/RNA_access.h
index 7d817f3dbe0..a61a9b3da85 100644
--- a/source/blender/makesrna/RNA_access.h
+++ b/source/blender/makesrna/RNA_access.h
@@ -898,10 +898,18 @@ char *RNA_path_append(const char *path, PointerRNA *ptr, PropertyRNA *prop,
                       int intkey, const char *strkey);
 char *RNA_path_back(const char *path);
 
-int RNA_path_resolve(PointerRNA *ptr, const char *path,
+/* path_resolve() variants only ensure that a valid pointer (and optionally property) exist */
+bool RNA_path_resolve(PointerRNA *ptr, const char *path,
                      PointerRNA *r_ptr, PropertyRNA **r_prop);
 
-int RNA_path_resolve_full(PointerRNA *ptr, const char *path,
+bool RNA_path_resolve_full(PointerRNA *ptr, const char *path,
+                          PointerRNA *r_ptr, PropertyRNA **r_prop, int *index);
+						  
+/* path_resolve_property() variants ensure that pointer + property both exist */
+bool RNA_path_resolve_property(PointerRNA *ptr, const char *path,
+                     PointerRNA *r_ptr, PropertyRNA **r_prop);
+
+bool RNA_path_resolve_property_full(PointerRNA *ptr, const char *path,
                           PointerRNA *r_ptr, PropertyRNA **r_prop, int *index);
 
 char *RNA_path_from_ID_to_struct(PointerRNA *ptr);
diff --git a/source/blender/makesrna/intern/rna_access.c b/source/blender/makesrna/intern/rna_access.c
index 9f36131a6c9..9a102c823a9 100644
--- a/source/blender/makesrna/intern/rna_access.c
+++ b/source/blender/makesrna/intern/rna_access.c
@@ -630,7 +630,7 @@ PropertyRNA *RNA_struct_find_property(PointerRNA *ptr, const char *identifier)
 		/* id prop lookup, not so common */
 		PropertyRNA *r_prop = NULL;
 		PointerRNA r_ptr; /* only support single level props */
-		if (RNA_path_resolve(ptr, identifier, &r_ptr, &r_prop) && r_ptr.type == ptr->type && r_ptr.data == ptr->data)
+		if (RNA_path_resolve(ptr, identifier, &r_ptr, &r_prop) && (r_ptr.type == ptr->type) && (r_ptr.data == ptr->data))
 			return r_prop;
 	}
 	else {
@@ -1533,7 +1533,7 @@ bool RNA_property_path_from_ID_check(PointerRNA *ptr, PropertyRNA *prop)
 		PropertyRNA *r_prop;
 
 		RNA_id_pointer_create(ptr->id.data, &id_ptr);
-		if (RNA_path_resolve(&id_ptr, path, &r_ptr, &r_prop) == TRUE) {
+		if (RNA_path_resolve(&id_ptr, path, &r_ptr, &r_prop) == true) {
 			ret = (prop == r_prop);
 		}
 		MEM_freeN(path);
@@ -3791,13 +3791,40 @@ static int rna_token_strip_quotes(char *token)
 	return 0;
 }
 
-/* Resolve the given RNA path to find the pointer+property indicated at the end of the path */
-int RNA_path_resolve(PointerRNA *ptr, const char *path, PointerRNA *r_ptr, PropertyRNA **r_prop)
+/* Resolve the given RNA Path to find both the pointer AND property indicated by fully resolving the path
+ * ! This is a convenience method to avoid logic errors and ugly syntax
+ * ! Assumes all pointers provided are valid
+ * > returns: True only if both a valid pointer and property are found after resolving the path 
+ */
+bool RNA_path_resolve_property(PointerRNA *ptr, const char *path, PointerRNA *r_ptr, PropertyRNA **r_prop)
+{
+	return RNA_path_resolve_full(ptr, path, r_ptr, r_prop, NULL) && (*r_prop != NULL);
+}
+
+/* Resolve the given RNA Path to find the pointer AND property (as well as the array index) indicated by fully resolving the path
+ * ! This is a convenience method to avoid logic errors and ugly syntax
+ * ! Assumes all pointers provided are valid
+ * > returns: True only if both a valid pointer and property are found after resolving the path
+ */
+bool RNA_path_resolve_property_full(PointerRNA *ptr, const char *path, PointerRNA *r_ptr, PropertyRNA **r_prop, int *index)
+{
+	return RNA_path_resolve_full(ptr, path, r_ptr, r_prop, index) && (*r_prop != NULL);
+}
+
+/* Resolve the given RNA Path to find the pointer and/or property indicated by fully resolving the path 
+ * ! Assumes all pointers provided are valid
+ * > returns: True if path can be resolved to a valid "pointer + property" OR "pointer only"
+ */
+bool RNA_path_resolve(PointerRNA *ptr, const char *path, PointerRNA *r_ptr, PropertyRNA **r_prop)
 {
 	return RNA_path_resolve_full(ptr, path, r_ptr, r_prop, NULL);
 }
 
-int RNA_path_resolve_full(PointerRNA *ptr, const char *path, PointerRNA *r_ptr, PropertyRNA **r_prop, int *index)
+/* Resolve the given RNA Path to find the pointer and/or property + array index indicated by fully resolving the path 
+ * ! Assumes all pointers provided are valid
+ * > returns: True if path can be resolved to a valid "pointer + property" OR "pointer only"
+ */
+bool RNA_path_resolve_full(PointerRNA *ptr, const char *path, PointerRNA *r_ptr, PropertyRNA **r_prop, int *index)
 {
 	PropertyRNA *prop;
 	PointerRNA curptr;
diff --git a/source/blender/python/intern/bpy_rna_anim.c b/source/blender/python/intern/bpy_rna_anim.c
index b61ed55da06..6e78a543481 100644
--- a/source/blender/python/intern/bpy_rna_anim.c
+++ b/source/blender/python/intern/bpy_rna_anim.c
@@ -72,7 +72,7 @@ static int pyrna_struct_anim_args_parse(
 	/* full paths can only be given from ID base */
 	if (is_idbase) {
 		int r_index = -1;
-		if (RNA_path_resolve_full(ptr, path, &r_ptr, &prop, &r_index) == 0) {
+		if (RNA_path_resolve_property_full(ptr, path, &r_ptr, &prop, &r_index) == false) {
 			prop = NULL;
 		}
 		else if (r_index != -1) {