PyAPI: Add PyC_UnicodeAsByteAndSize

Read the string length from Python directly when assigning id-properties

source/blender/blenkernel/intern/idprop.c

@@ -940,17 +940,18 @@ IDProperty *IDP_New(const char type, const IDPropertyTemplate *val, const char *
 				prop->subtype = IDP_STRING_SUB_BYTE;
 			}
 			else {
-				if (st == NULL) {
+				if (st == NULL || val->string.len <= 1) {
 					prop->data.pointer = MEM_mallocN(DEFAULT_ALLOC_FOR_NULL_STRINGS, "id property string 1");
 					*IDP_String(prop) = '\0';
 					prop->totallen = DEFAULT_ALLOC_FOR_NULL_STRINGS;
 					prop->len = 1; /*NULL string, has len of 1 to account for null byte.*/
 				}
 				else {
-					int stlen = (int)strlen(st) + 1;
-					prop->data.pointer = MEM_mallocN((size_t)stlen, "id property string 3");
-					prop->len = prop->totallen = stlen;
-					memcpy(prop->data.pointer, st, (size_t)stlen);
+					BLI_assert((int)val->string.len <= (int)strlen(st) + 1);
+					prop->data.pointer = MEM_mallocN((size_t)val->string.len, "id property string 3");
+					memcpy(prop->data.pointer, st, (size_t)val->string.len - 1);
+					IDP_String(prop)[val->string.len - 1] = '\0';
+					prop->len = prop->totallen = val->string.len;
 				}
 				prop->subtype = IDP_STRING_SUB_UTF8;
 			}

source/blender/python/generic/idprop_py_api.c

@@ -378,8 +378,10 @@ bool BPy_IDProperty_Map_ValidateAndCreate(PyObject *name_obj, IDProperty *group,
 	}
 	else if (PyUnicode_Check(ob)) {
 #ifdef USE_STRING_COERCE
+		Py_ssize_t value_size;
 		PyObject *value_coerce = NULL;
-		val.string.str = PyC_UnicodeAsByte(ob, &value_coerce);
+		val.string.str = PyC_UnicodeAsByteAndSize(ob, &value_size, &value_coerce);
+		val.string.len = (int)value_size + 1;
 		val.string.subtype = IDP_STRING_SUB_UTF8;
 		prop = IDP_New(IDP_STRING, &val, name);
 		Py_XDECREF(value_coerce);

source/blender/python/generic/py_capi_utils.c

@@ -540,6 +540,35 @@ PyObject *PyC_ExceptionBuffer_Simple(void)
 }
 
 /* string conversion, escape non-unicode chars, coerce must be set to NULL */
+const char *PyC_UnicodeAsByteAndSize(PyObject *py_str, Py_ssize_t *size, PyObject **coerce)
+{
+	const char *result;
+
+	result = _PyUnicode_AsStringAndSize(py_str, size);
+
+	if (result) {
+		/* 99% of the time this is enough but we better support non unicode
+		 * chars since blender doesnt limit this */
+		return result;
+	}
+	else {
+		PyErr_Clear();
+
+		if (PyBytes_Check(py_str)) {
+			*size = PyBytes_GET_SIZE(py_str);
+			return PyBytes_AS_STRING(py_str);
+		}
+		else if ((*coerce = PyUnicode_EncodeFSDefault(py_str))) {
+			*size = PyBytes_GET_SIZE(*coerce);
+			return PyBytes_AS_STRING(*coerce);
+		}
+		else {
+			/* leave error raised from EncodeFS */
+			return NULL;
+		}
+	}
+}
+
 const char *PyC_UnicodeAsByte(PyObject *py_str, PyObject **coerce)
 {
 	const char *result;

source/blender/python/generic/py_capi_utils.h

@@ -53,6 +53,7 @@ void            PyC_List_Fill(PyObject *list, PyObject *value);
 PyObject *      PyC_UnicodeFromByte(const char *str);
 PyObject *      PyC_UnicodeFromByteAndSize(const char *str, Py_ssize_t size);
 const char *    PyC_UnicodeAsByte(PyObject *py_str, PyObject **coerce); /* coerce must be NULL */
+const char *    PyC_UnicodeAsByteAndSize(PyObject *py_str, Py_ssize_t *size, PyObject **coerce);
 
 /* name namespace function for bpy & bge */
 PyObject *		PyC_DefaultNameSpace(const char *filename);