Correct handling of mailto: links

Resolves #2613

Author: Gerrit0

Diff for: CHANGELOG.md

@@ -1,7 +1,8 @@
 # Unreleased
 
-### Features
+### Bug Fixes
 
+-   `mailto:` links are no longer incorrectly recognized as relative paths, #2613.
 -   Added `@since` to the default list of recognized tags, #2614.
 
 ## v0.26.2 (2024-06-24)

Diff for: src/lib/converter/comments/textParser.ts

@@ -189,7 +189,7 @@ function checkMarkdownLink(
         if (link.ok) {
             // Only make a relative-link display part if it's actually a relative link.
             // Discard protocol:// links, unix style absolute paths, and windows style absolute paths.
-            if (isRelativeLink(link.str)) {
+            if (isRelativePath(link.str)) {
                 return {
                     pos: labelEnd + 2,
                     end: link.pos,
@@ -240,7 +240,7 @@ function checkReference(data: TextParserData): RelativeLink | undefined {
                 );
 
                 if (link.ok) {
-                    if (isRelativeLink(link.str)) {
+                    if (isRelativePath(link.str)) {
                         return {
                             pos: lookahead,
                             end: link.pos,
@@ -284,7 +284,7 @@ function checkAttribute(
         ) {
             parser.step();
 
-            if (isRelativeLink(parser.currentAttributeValue)) {
+            if (isRelativePath(parser.currentAttributeValue)) {
                 data.pos = parser.pos;
                 return {
                     pos: parser.currentAttributeValueStart,
@@ -302,8 +302,14 @@ function checkAttribute(
     }
 }
 
-function isRelativeLink(link: string) {
-    return !/^[a-z]+:\/\/|^\/|^[a-z]:\\|^#/i.test(link);
+function isRelativePath(link: string) {
+    // Lots of edge cases encoded right here!
+    // Originally, this attempted to match protocol://, but...
+    // `mailto:[email protected]` is not a relative path
+    // `C:\foo` is not a relative path
+    // `/etc/passwd` is not a relative path
+    // `#anchor` is not a relative path
+    return !/^[a-z]+:|^\/|^#/i.test(link);
 }
 
 function findLabelEnd(text: string, pos: number) {

Diff for: src/test/comments.test.ts

@@ -1440,6 +1440,16 @@ describe("Comment Parser", () => {
         ] satisfies CommentDisplayPart[]);
     });
 
+    it("Does not mistake mailto: links as relative paths", () => {
+        const comment = getComment(`/**
+            * [1]: mailto:[email protected]
+            */`);
+
+        equal(comment.summary, [
+            { kind: "text", text: "[1]: mailto:[email protected]" },
+        ] satisfies CommentDisplayPart[]);
+    });
+
     it("Recognizes HTML image links", () => {
         const comment = getComment(`/**
         * <img width=100 height="200" src="./test.png" >