modify the python context access so invalid names will raise an exception rather then returning None.

this way the UI scripts are less likely to fail silently and wont let typos work ok.

also allow subclassing of the context, added a copy function,
 bpy.context.copy(), returns the context as a python dict to be modified and used in python.

This also showed up an invalid brush member in the screen context.

1 files changed, 36 insertions, 17 deletions

diff --git a/source/blender/blenkernel/intern/context.c b/source/blender/blenkernel/intern/context.c
index 7f2872c0797..1cd0e6cd677 100644
--- a/source/blender/blenkernel/intern/context.c
+++ b/source/blender/blenkernel/intern/context.c
@@ -408,6 +408,7 @@ struct bContextDataResult {
 static int ctx_data_get(bContext *C, const char *member, bContextDataResult *result)
 {
 	int done= 0, recursion= C->data.recursion;
+	int ret= 0;
 
 	memset(result, 0, sizeof(bContextDataResult));
 
@@ -417,7 +418,14 @@ static int ctx_data_get(bContext *C, const char *member, bContextDataResult *res
 
 	/* we check recursion to ensure that we do not get infinite
 	 * loops requesting data from ourselfs in a context callback */
-	if(!done && recursion < 1 && C->wm.store) {
+
+	/* Ok, this looks evil...
+	 * if(ret) done= -(-ret | -done);
+	 *
+	 * Values in order of importance
+	 * (0, -1, 1) - Where 1 is highest priority
+	 * */
+	if(done!=1 && recursion < 1 && C->wm.store) {
 		bContextStoreEntry *entry;
 
 		C->data.recursion= 1;
@@ -429,21 +437,28 @@ static int ctx_data_get(bContext *C, const char *member, bContextDataResult *res
 			}
 		}
 	}
-	if(!done && recursion < 2 && C->wm.region) {
+	if(done!=1 && recursion < 2 && C->wm.region) {
 		C->data.recursion= 2;
-		if(C->wm.region->type && C->wm.region->type->context)
-			done= C->wm.region->type->context(C, member, result);
+		if(C->wm.region->type && C->wm.region->type->context) {
+			ret = C->wm.region->type->context(C, member, result);
+			if(ret) done= -(-ret | -done);
+
+		}
 	}
-	if(!done && recursion < 3 && C->wm.area) {
+	if(done!=1 && recursion < 3 && C->wm.area) {
 		C->data.recursion= 3;
-		if(C->wm.area->type && C->wm.area->type->context)
-			done= C->wm.area->type->context(C, member, result);
+		if(C->wm.area->type && C->wm.area->type->context) {
+			ret = C->wm.area->type->context(C, member, result);
+			if(ret) done= -(-ret | -done);
+		}
 	}
-	if(!done && recursion < 4 && C->wm.screen) {
+	if(done!=1 && recursion < 4 && C->wm.screen) {
 		bContextDataCallback cb= C->wm.screen->context;
 		C->data.recursion= 4;
-		if(cb)
-			done= cb(C, member, result);
+		if(cb) {
+			ret = cb(C, member, result);
+			if(ret) done= -(-ret | -done);
+		}
 	}
 
 	C->data.recursion= recursion;
@@ -455,7 +470,7 @@ static void *ctx_data_pointer_get(const bContext *C, const char *member)
 {
 	bContextDataResult result;
 
-	if(C && ctx_data_get((bContext*)C, member, &result))
+	if(C && ctx_data_get((bContext*)C, member, &result)==1)
 		return result.ptr.data;
 
 	return NULL;
@@ -465,7 +480,7 @@ static int ctx_data_pointer_verify(const bContext *C, const char *member, void *
 {
 	bContextDataResult result;
 
-	if(ctx_data_get((bContext*)C, member, &result)) {
+	if(ctx_data_get((bContext*)C, member, &result)==1) {
 		*pointer= result.ptr.data;
 		return 1;
 	}
@@ -479,7 +494,7 @@ static int ctx_data_collection_get(const bContext *C, const char *member, ListBa
 {
 	bContextDataResult result;
 
-	if(ctx_data_get((bContext*)C, member, &result)) {
+	if(ctx_data_get((bContext*)C, member, &result)==1) {
 		*list= result.list;
 		return 1;
 	}
@@ -494,7 +509,7 @@ PointerRNA CTX_data_pointer_get(const bContext *C, const char *member)
 {
 	bContextDataResult result;
 
-	if(ctx_data_get((bContext*)C, member, &result))
+	if(ctx_data_get((bContext*)C, member, &result)==1)
 		return result.ptr;
 	else
 		return PointerRNA_NULL;
@@ -514,7 +529,7 @@ ListBase CTX_data_collection_get(const bContext *C, const char *member)
 {
 	bContextDataResult result;
 
-	if(ctx_data_get((bContext*)C, member, &result)) {
+	if(ctx_data_get((bContext*)C, member, &result)==1) {
 		return result.list;
 	}
 	else {
@@ -524,11 +539,13 @@ ListBase CTX_data_collection_get(const bContext *C, const char *member)
 	}
 }
 
-void CTX_data_get(const bContext *C, const char *member, PointerRNA *r_ptr, ListBase *r_lb)
+/* 1:found,  -1:found but not set,  0:not found */
+int CTX_data_get(const bContext *C, const char *member, PointerRNA *r_ptr, ListBase *r_lb)
 {
 	bContextDataResult result;
+	int ret= ctx_data_get((bContext*)C, member, &result);
 
-	if(ctx_data_get((bContext*)C, member, &result)) {
+	if(ret==1) {
 		*r_ptr= result.ptr;
 		*r_lb= result.list;
 	}
@@ -536,6 +553,8 @@ void CTX_data_get(const bContext *C, const char *member, PointerRNA *r_ptr, List
 		memset(r_ptr, 0, sizeof(*r_ptr));
 		memset(r_lb, 0, sizeof(*r_lb));
 	}
+
+	return ret;
 }
 
 static void data_dir_add(ListBase *lb, const char *member)