fix [#28658] python can assign non utf8 and crash because of string lenth limits.

add BLI_strncpy_utf8() which which ensures there are no partially copied UTF8 characters, limited by the buffer size.

4 files changed, 52 insertions, 5 deletions

diff --git a/source/blender/blenlib/BLI_string.h b/source/blender/blenlib/BLI_string.h
index be77e18c24b..c53ce9dced5 100644
--- a/source/blender/blenlib/BLI_string.h
+++ b/source/blender/blenlib/BLI_string.h
@@ -144,6 +144,7 @@ void BLI_ascii_strtoupper(char *str, int len);
 
 
 /* string_utf8.c - may move these into their own header some day - campbell */
+char *BLI_strncpy_utf8(char *dst, const char *src, size_t maxncpy);
 int BLI_utf8_invalid_byte(const char *str, int length);
 int BLI_utf8_invalid_strip(char *str, int length);
 
diff --git a/source/blender/blenlib/intern/string_utf8.c b/source/blender/blenlib/intern/string_utf8.c
index 8f7e4518e03..5c37d3003e4 100644
--- a/source/blender/blenlib/intern/string_utf8.c
+++ b/source/blender/blenlib/intern/string_utf8.c
@@ -141,3 +141,43 @@ int BLI_utf8_invalid_strip(char *str, int length)
 
 	return tot;
 }
+
+
+/* compatible with BLI_strncpy, but esnure no partial utf8 chars */
+
+/* array copied from glib's glib's gutf8.c,
+ * note: this looks to be at odd's with 'trailingBytesForUTF8',
+ * need to find out what gives here! - campbell */
+static const size_t utf8_skip_data[256] = {
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
+  3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,6,6,1,1
+};
+
+char *BLI_strncpy_utf8(char *dst, const char *src, size_t maxncpy)
+{
+	char *dst_r= dst;
+	size_t utf8_size;
+
+	/* note: currently we dont attempt to deal with invalid utf8 chars */
+
+	while(*src != '\0' && (utf8_size= utf8_skip_data[*src]) < maxncpy) {
+		maxncpy -= utf8_size;
+		switch(utf8_size) {
+			case 6: *dst ++ = *src ++;
+			case 5: *dst ++ = *src ++;
+			case 4: *dst ++ = *src ++;
+			case 3: *dst ++ = *src ++;
+			case 2: *dst ++ = *src ++;
+			case 1: *dst ++ = *src ++;
+		}
+	}
+	*dst= '\0';
+	return dst_r;
+}
+
diff --git a/source/blender/makesrna/intern/makesrna.c b/source/blender/makesrna/intern/makesrna.c
index bc30210bfbb..23100fa8bd7 100644
--- a/source/blender/makesrna/intern/makesrna.c
+++ b/source/blender/makesrna/intern/makesrna.c
@@ -522,11 +522,14 @@ static char *rna_def_property_get_func(FILE *f, StructRNA *srna, PropertyRNA *pr
 				fprintf(f, "	%s(ptr, value);\n", manualfunc);
 			}
 			else {
+				const PropertySubType subtype= prop->subtype;
+				const char *string_copy_func= (subtype==PROP_FILEPATH || subtype==PROP_DIRPATH || subtype==PROP_FILENAME) ? "BLI_strncpy" : "BLI_strncpy_utf8";
+
 				rna_print_data_get(f, dp);
 				if(sprop->maxlength)
-					fprintf(f, "	BLI_strncpy(value, data->%s, %d);\n", dp->dnaname, sprop->maxlength);
+					fprintf(f, "	%s(value, data->%s, %d);\n", string_copy_func, dp->dnaname, sprop->maxlength);
 				else
-					fprintf(f, "	BLI_strncpy(value, data->%s, sizeof(data->%s));\n", dp->dnaname, dp->dnaname);
+					fprintf(f, "	%s(value, data->%s, sizeof(data->%s));\n", string_copy_func, dp->dnaname, dp->dnaname);
 			}
 			fprintf(f, "}\n\n");
 			break;
@@ -734,11 +737,14 @@ static char *rna_def_property_set_func(FILE *f, StructRNA *srna, PropertyRNA *pr
 				fprintf(f, "	%s(ptr, value);\n", manualfunc);
 			}
 			else {
+				const PropertySubType subtype= prop->subtype;
+				const char *string_copy_func= (subtype==PROP_FILEPATH || subtype==PROP_DIRPATH || subtype==PROP_FILENAME) ? "BLI_strncpy" : "BLI_strncpy_utf8";
+
 				rna_print_data_get(f, dp);
 				if(sprop->maxlength)
-					fprintf(f, "	BLI_strncpy(data->%s, value, %d);\n", dp->dnaname, sprop->maxlength);
+					fprintf(f, "	%s(data->%s, value, %d);\n", string_copy_func, dp->dnaname, sprop->maxlength);
 				else
-					fprintf(f, "	BLI_strncpy(data->%s, value, sizeof(data->%s));\n", dp->dnaname, dp->dnaname);
+					fprintf(f, "	%s(data->%s, value, sizeof(data->%s));\n", string_copy_func, dp->dnaname, dp->dnaname);
 			}
 			fprintf(f, "}\n\n");
 			break;
diff --git a/source/blender/makesrna/intern/rna_ID.c b/source/blender/makesrna/intern/rna_ID.c
index 82217cdc3e4..05786cedeac 100644
--- a/source/blender/makesrna/intern/rna_ID.c
+++ b/source/blender/makesrna/intern/rna_ID.c
@@ -99,7 +99,7 @@ int rna_ID_name_length(PointerRNA *ptr)
 void rna_ID_name_set(PointerRNA *ptr, const char *value)
 {
 	ID *id= (ID*)ptr->data;
-	BLI_strncpy(id->name+2, value, sizeof(id->name)-2);
+	BLI_strncpy_utf8(id->name+2, value, sizeof(id->name)-2);
 	test_idbutton(id->name+2);
 }