comment array/collection skip(), since there was some confusion in this area which caused bugs on index lookups.

2 files changed, 10 insertions, 3 deletions

diff --git a/source/blender/makesrna/intern/makesrna.c b/source/blender/makesrna/intern/makesrna.c
index 2036833fa37..cf1b14d5e62 100644
--- a/source/blender/makesrna/intern/makesrna.c
+++ b/source/blender/makesrna/intern/makesrna.c
@@ -948,6 +948,8 @@ static char *rna_def_property_begin_func(FILE *f, StructRNA *srna, PropertyRNA *
 
 static char *rna_def_property_lookup_int_func(FILE *f, StructRNA *srna, PropertyRNA *prop, PropertyDefRNA *dp, char *manualfunc, char *nextfunc)
 {
+	/* note on indicies, this is for external functions and ignores skipped values.
+	 * so the the index can only be checked against the length when there is no 'skip' funcion. */
 	char *func;
 
 	if(prop->flag & PROP_IDPROPERTY && manualfunc==NULL)
@@ -984,9 +986,9 @@ static char *rna_def_property_lookup_int_func(FILE *f, StructRNA *srna, Property
 		fprintf(f, "		ArrayIterator *internal= iter.internal;\n");
 		fprintf(f, "		if(index < 0 || index >= internal->length) {\n");
 		fprintf(f, "#ifdef __GNUC__\n");
-		fprintf(f, "			printf(\"Array iterator out of range: %%s (index %%d range %%d)\\n\", __func__, index, internal->length);  \n");
+		fprintf(f, "			printf(\"Array iterator out of range: %%s (index %%d)\\n\", __func__, index);\n");
 		fprintf(f, "#else\n");
-		fprintf(f, "			printf(\"Array iterator out of range: (index %%d range %%d)\\n\", index, internal->length);  \n");
+		fprintf(f, "			printf(\"Array iterator out of range: (index %%d)\\n\", index);\n");
 		fprintf(f, "#endif\n");
 		fprintf(f, "		}\n");
 		fprintf(f, "		else if(internal->skip) {\n");
diff --git a/source/blender/makesrna/intern/rna_internal.h b/source/blender/makesrna/intern/rna_internal.h
index 39f12c56e1c..a512bb93d6b 100644
--- a/source/blender/makesrna/intern/rna_internal.h
+++ b/source/blender/makesrna/intern/rna_internal.h
@@ -321,10 +321,15 @@ PointerRNA rna_listbase_lookup_int(PointerRNA *ptr, StructRNA *type, struct List
 
 typedef struct ArrayIterator {
 	char *ptr;
-	char *endptr;
+	char *endptr;	/* past the last valid pointer, only for comparisons, ignores skipped values */
 	void *free_ptr; /* will be free'd if set */
 	int itemsize;
+
+	/* array length with no skip functins applied, take care not to compare against index from animsys or python indicies */
 	int length;
+
+	/* optional skip function, when set the array as viewed by rna can contain only a subset of the members.
+	 * this changes indicies so quick array index lookups are not possible when skip function is used. */
 	IteratorSkipFunc skip;
 } ArrayIterator;