patch 8.0.0171: JS style JSON does not support single quotes

Problem:    JS style JSON does not support single quotes.
Solution:   Allow for single quotes. (Yasuhiro Matsumoto, closes #1371)

runtime/doc/eval.txt

@@ -5229,6 +5229,7 @@ join({list} [, {sep}])					*join()*
 js_decode({string})					*js_decode()*
 		This is similar to |json_decode()| with these differences:
 		- Object key names do not have to be in quotes.
+		- Strings can be in single quotes.
 		- Empty items in an array (between two commas) are allowed and
 		  result in v:none items.
 

src/json.c

@@ -378,7 +378,7 @@ json_skip_white(js_read_T *reader)
 }
 
     static int
-json_decode_string(js_read_T *reader, typval_T *res)
+json_decode_string(js_read_T *reader, typval_T *res, int quote)
 {
     garray_T    ga;
     int		len;
@@ -389,8 +389,8 @@ json_decode_string(js_read_T *reader, typval_T *res)
     if (res != NULL)
 	ga_init2(&ga, 1, 200);
 
-    p = reader->js_buf + reader->js_used + 1; /* skip over " */
-    while (*p != '"')
+    p = reader->js_buf + reader->js_used + 1; /* skip over " or ' */
+    while (*p != quote)
     {
 	/* The JSON is always expected to be utf-8, thus use utf functions
 	 * here. The string is converted below if needed. */
@@ -504,7 +504,7 @@ json_decode_string(js_read_T *reader, typval_T *res)
     }
 
     reader->js_used = (int)(p - reader->js_buf);
-    if (*p == '"')
+    if (*p == quote)
     {
 	++reader->js_used;
 	if (res != NULL)
@@ -620,7 +620,8 @@ json_decode_item(js_read_T *reader, typval_T *res, int options)
 
 	if (top_item != NULL && top_item->jd_type == JSON_OBJECT_KEY
 		&& (options & JSON_JS)
-		&& reader->js_buf[reader->js_used] != '"')
+		&& reader->js_buf[reader->js_used] != '"'
+		&& reader->js_buf[reader->js_used] != '\'')
 	{
 	    char_u *key;
 
@@ -690,7 +691,17 @@ json_decode_item(js_read_T *reader, typval_T *res, int options)
 		    continue;
 
 		case '"': /* string */
-		    retval = json_decode_string(reader, cur_item);
+		    retval = json_decode_string(reader, cur_item, *p);
+		    break;
+
+		case '\'':
+		    if (options & JSON_JS)
+			retval = json_decode_string(reader, cur_item, *p);
+		    else
+		    {
+			EMSG(_(e_invarg));
+			retval = FAIL;
+		    }
 		    break;
 
 		case ',': /* comma: empty item */

src/json_test.c

@@ -181,7 +181,7 @@ test_fill_called_on_string(void)
     reader.js_buf = (char_u *)" \"foo";
     reader.js_end = reader.js_buf + STRLEN(reader.js_buf);
     reader.js_cookie =        " \"foobar\"  ";
-    assert(json_decode_string(&reader, NULL) == OK);
+    assert(json_decode_string(&reader, NULL, '"') == OK);
 }
 #endif
 

src/testdir/test_json.vim

@@ -145,6 +145,8 @@ func Test_json_decode()
   call assert_equal("", json_decode('""'))
 
   call assert_equal({'n': 1}, json_decode('{"n":1,}'))
+  call assert_fails("call json_decode(\"{'n':'1',}\")", 'E474:')
+  call assert_fails("call json_decode(\"'n'\")", 'E474:')
 
   call assert_fails('call json_decode("\"")', "E474:")
   call assert_fails('call json_decode("blah")', "E474:")
@@ -255,8 +257,11 @@ func Test_js_decode()
   call assert_equal(v:none, js_decode(''))
   call assert_equal(type(v:none), type(js_decode('')))
   call assert_equal("", js_decode('""'))
+  call assert_equal("", js_decode("''"))
 
+  call assert_equal('n', js_decode("'n'"))
   call assert_equal({'n': 1}, js_decode('{"n":1,}'))
+  call assert_equal({'n': '1'}, js_decode("{'n':'1',}"))
 
   call assert_fails('call js_decode("\"")', "E474:")
   call assert_fails('call js_decode("blah")', "E474:")

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    171,
 /**/
     170,
 /**/