Fix rendering of removed votes in Change Log

Change 251800 was too aggressive with removing information on
"Patch set $N: ...: lines. For normal votes the removal was fine,
because it was redundant information. But the dedicated vote chips
did not work for vote removals. So with this change we keep being
aggressive and remove the entire "Patch Set $N: ..." line, but we
create vote chips also for vote removals.

Change-Id: Ia721552f08528c76bde469ed85b76d12783b761b

polygerrit-ui/app/elements/change/gr-message/gr-message.html

@@ -156,6 +156,9 @@ limitations under the License.
       .commentsIcon {
         vertical-align: top;
       }
+      .score.removed {
+        background-color: var(--vote-color-neutral);
+      }
       .score.negative {
         background-color: var(--vote-color-disliked);
       }
@@ -195,7 +198,7 @@ limitations under the License.
             on behalf of
           </span>
           <gr-account-label account="[[author]]" class="authorLabel"></gr-account-label>
-          <template is="dom-repeat" items="[[_getScores(message)]]" as="score">
+          <template is="dom-repeat" items="[[_getScores(message, labelExtremes)]]" as="score">
             <span class$="score [[_computeScoreClass(score, labelExtremes)]]">
               [[score.label]] [[score.value]]
             </span>

polygerrit-ui/app/elements/change/gr-message/gr-message.js

@@ -18,7 +18,7 @@
   'use strict';
 
   const PATCH_SET_PREFIX_PATTERN = /^Patch Set \d+:\s*(.*)/;
-  const LABEL_TITLE_SCORE_PATTERN = /^([A-Za-z0-9-]+)([+-]\d+)$/;
+  const LABEL_TITLE_SCORE_PATTERN = /^(-?)([A-Za-z0-9-]+?)([+-]\d+)?$/;
 
   /**
    * @appliesMixin Gerrit.FireMixin
@@ -274,17 +274,28 @@
       return event.type === 'REVIEWER_UPDATE';
     }
 
-    _getScores(message) {
-      if (!message.message) { return []; }
+    _getScores(message, labelExtremes) {
+      if (!message || !message.message || !labelExtremes) {
+        return [];
+      }
       const line = message.message.split('\n', 1)[0];
       const patchSetPrefix = PATCH_SET_PREFIX_PATTERN;
-      if (!line.match(patchSetPrefix)) { return []; }
+      if (!line.match(patchSetPrefix)) {
+        return [];
+      }
       const scoresRaw = line.split(patchSetPrefix)[1];
-      if (!scoresRaw) { return []; }
+      if (!scoresRaw) {
+        return [];
+      }
       return scoresRaw.split(' ')
           .map(s => s.match(LABEL_TITLE_SCORE_PATTERN))
-          .filter(ms => ms && ms.length === 3)
-          .map(ms => { return {label: ms[1], value: ms[2]}; });
+          .filter(ms =>
+            ms && ms.length === 4 && labelExtremes.hasOwnProperty(ms[2]))
+          .map(ms => {
+            const label = ms[2];
+            const value = ms[1] === '-' ? 'removed' : ms[3];
+            return {label, value};
+          });
     }
 
     _computeScoreClass(score, labelExtremes) {
@@ -292,6 +303,9 @@
       if ([score, labelExtremes].some(arg => arg === undefined)) {
         return '';
       }
+      if (score.value === 'removed') {
+        return 'removed';
+      }
       const classes = [];
       if (score.value > 0) {
         classes.push('positive');

polygerrit-ui/app/elements/change/gr-message/gr-message_test.html

@@ -244,12 +244,12 @@ limitations under the License.
       element.message = {
         author: {},
         expanded: false,
-        message: 'Patch Set 1: Verified+1 Code-Review-2 Trybot-Ready+1',
+        message: 'Patch Set 1: Verified+1 Code-Review-2 Trybot-Label3+1 Blub+1',
       };
       element.labelExtremes = {
         'Verified': {max: 1, min: -1},
         'Code-Review': {max: 2, min: -2},
-        'Trybot-Ready': {max: 3, min: 0},
+        'Trybot-Label3': {max: 3, min: 0},
       };
       flushAsynchronousOperations();
       const scoreChips = Polymer.dom(element.root).querySelectorAll('.score');
@@ -265,6 +265,25 @@ limitations under the License.
       assert.isFalse(scoreChips[2].classList.contains('min'));
     });
 
+    test('removed votes', () => {
+      element.message = {
+        author: {},
+        expanded: false,
+        message: 'Patch Set 1: Verified+1 -Code-Review -Commit-Queue',
+      };
+      element.labelExtremes = {
+        'Verified': {max: 1, min: -1},
+        'Code-Review': {max: 2, min: -2},
+        'Commit-Queue': {max: 3, min: 0},
+      };
+      flushAsynchronousOperations();
+      const scoreChips = Polymer.dom(element.root).querySelectorAll('.score');
+      assert.equal(scoreChips.length, 3);
+
+      assert.isTrue(scoreChips[1].classList.contains('removed'));
+      assert.isTrue(scoreChips[2].classList.contains('removed'));
+    });
+
     test('false negative vote', () => {
       element.message = {
         author: {},