Added some clarity around validation of characters

stevenlaidlaw · stevenlaidlaw · commit 2aa10c923254 · 2022-08-24T15:31:12.000+08:00
diff --git a/extensions/autolink.c b/extensions/autolink.c
@@ -272,13 +272,17 @@ static cmark_node *match(cmark_syntax_extension *ext, cmark_parser *parser,
 static bool validate_protocol(char protocol[], uint8_t *data, int rewind) {
   size_t len = strlen(protocol);
 
+  // Check that the protocol matches
   for (int i = 1; i <= len; i++) {
     if (data[-rewind - i] != protocol[len - i]) {
       return false;
     }
   }
 
-  return !cmark_isalnum(data[-rewind - len - 1]);
+  char prev_char = data[-rewind - len - 1];
+
+  // Make sure the character before the protocol is non-alphanumeric
+  return !cmark_isalnum(prev_char);
 }
 
 static void postprocess_text(cmark_parser *parser, cmark_node *text, int offset, int depth) {

Original file line number	Diff line number	Diff line change
`@@ -272,13 +272,17 @@ static cmark_node match(cmark_syntax_extension ext, cmark_parser *parser,`
`272`	`272`	`static bool validate_protocol(char protocol[], uint8_t *data, int rewind) {`
`273`	`273`	`size_t len = strlen(protocol);`
`274`	`274`
	`275`	`+ // Check that the protocol matches`
`275`	`276`	`for (int i = 1; i <= len; i++) {`
`276`	`277`	`if (data[-rewind - i] != protocol[len - i]) {`
`277`	`278`	`return false;`
`278`	`279`	`}`
`279`	`280`	`}`
`280`	`281`
`281`		`- return !cmark_isalnum(data[-rewind - len - 1]);`
	`282`	`+ char prev_char = data[-rewind - len - 1];`
	`283`	`+`
	`284`	`+ // Make sure the character before the protocol is non-alphanumeric`
	`285`	`+ return !cmark_isalnum(prev_char);`
`282`	`286`	`}`
`283`	`287`
`284`	`288`	`static void postprocess_text(cmark_parser parser, cmark_node text, int offset, int depth) {`