Fix commentlinks with same prefix in pattern and link

If using the commentlinks.%NAME%.links option and having the same prefix
in the pattern and the url, the parsing did not work properly.
For example:

  [commentlink "test"]
    pattern = [Hh][Tt][Tt][Pp]example
    link = http://example.com

and the line in the message:

  httpexample 1234

would result in:

  http<a href="://example.com" ...>httpexample 1234</a>

This bug was introduced in a change implementing the possibility to
have overlapping patterns, e.g. allowing a comma-separated list of
issue ids. (commit: fb48902ef303d008c6f0dd38d654106c00313530). This
would have however anyway only worked for the `html`-variant of
comment links, which allow to directly provide html-elements as a
substitute for the text matching the pattern.

Thus, this change restricts the logic introduced in the above mentioned
commit to the html-variant.

Bug: Issue 12197
Change-Id: I9efd9308f2b40f3fec8405c93849d13d4576562a

2 files changed, 26 insertions, 9 deletions

diff --git a/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.html b/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.html
index 6d413b7fab..19839a8c57 100644
--- a/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.html
+++ b/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.html
@@ -50,6 +50,10 @@ limitations under the License.
           match: '([Bb]ug|[Ii]ssue)\\s*#?(\\d+)',
           link: 'https://bugs.chromium.org/p/gerrit/issues/detail?id=$2',
         },
+        prefixsameinlinkandpattern: {
+          match: '([Hh][Tt][Tt][Pp]example)\\s*#?(\\d+)',
+          link: 'https://bugs.chromium.org/p/gerrit/issues/detail?id=$2',
+        },
         changeid: {
           match: '(I[0-9a-f]{8,40})',
           link: '#/q/$1',
@@ -116,6 +120,18 @@ limitations under the License.
       assert.equal(linkEl.textContent, 'Bug 3650');
     });
 
+    test('Pattern with same prefix as link was correctly parsed', () => {
+      // Pattern starts with the same prefix (`http`) as the url.
+      element.content = 'httpexample 3650';
+
+      assert.equal(element.$.output.childNodes.length, 1);
+      const linkEl = element.$.output.childNodes[0];
+      const url = 'https://bugs.chromium.org/p/gerrit/issues/detail?id=3650';
+      assert.equal(linkEl.target, '_blank');
+      assert.equal(linkEl.href, url);
+      assert.equal(linkEl.textContent, 'httpexample 3650');
+    });
+
     test('Change-Id pattern was parsed and linked', () => {
       // "Change-Id:" pattern.
       const changeID = 'I11d6a37f5e9b5df0486f6c922d8836dfa780e03e';
diff --git a/polygerrit-ui/app/elements/shared/gr-linked-text/link-text-parser.js b/polygerrit-ui/app/elements/shared/gr-linked-text/link-text-parser.js
index 23a71f99e3..027c632e12 100644
--- a/polygerrit-ui/app/elements/shared/gr-linked-text/link-text-parser.js
+++ b/polygerrit-ui/app/elements/shared/gr-linked-text/link-text-parser.js
@@ -312,14 +312,15 @@
         let result = match[0].replace(pattern,
             patterns[p].html || patterns[p].link);
 
-        let i;
-        // Skip portion of replacement string that is equal to original.
-        for (i = 0; i < result.length; i++) {
-          if (result[i] !== match[0][i]) { break; }
-        }
-        result = result.slice(i);
-
         if (patterns[p].html) {
+          let i;
+          // Skip portion of replacement string that is equal to original to
+          // allow overlapping patterns.
+          for (i = 0; i < result.length; i++) {
+            if (result[i] !== match[0][i]) { break; }
+          }
+          result = result.slice(i);
+
           this.addHTML(
               result,
               susbtrIndex + match.index + i,
@@ -329,8 +330,8 @@
           this.addLink(
               match[0],
               result,
-              susbtrIndex + match.index + i,
-              match[0].length - i,
+              susbtrIndex + match.index,
+              match[0].length,
               outputArray);
         } else {
           throw Error('linkconfig entry ' + p +