commit 21b5ccb8aae3224794082fc768a08a55716c40ad
Author: Ben Rohlfs <brohlfs@google.com>
Date:   Tue Oct 6 14:51:38 2020 +0200

    Fix the dangling comma after reviewer on dashboard
    
    We cannot hide the comma based on simple css :last-of-type, because we
    also have to take the additional reviewers into account. And from a css
    perspective we cannot be sure about their presence, because
    :last-of-type does not care about display:none being present or not.
    
    Change-Id: I6d2da48da83584a961b1b660a1ea94f8693ad57d

diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.ts
index 20cc207..5a345f2 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.ts
@@ -408,6 +408,16 @@ export class GrChangeListItem extends ChangeTableMixin(
       isOwner: selfId === ownerId,
     });
   }
+
+  _computeCommaHidden(index?: number, change?: ChangeInfo) {
+    if (index === undefined) return false;
+    if (change === undefined) return false;
+
+    const additionalCount = this._computeAdditionalReviewersCount(change);
+    const primaryCount = this._computePrimaryReviewers(change).length;
+    const isLast = index === primaryCount - 1;
+    return isLast && additionalCount === 0;
+  }
 }
 
 declare global {
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_html.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_html.ts
index 5316fe5..497ed1e 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_html.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_html.ts
@@ -113,9 +113,6 @@ export const htmlTemplate = html`
     .cell.label iron-icon {
       vertical-align: top;
     }
-    .lastChildHidden:last-of-type {
-      display: none;
-    }
     @media only screen and (max-width: 50em) {
       :host {
         display: flex;
@@ -197,6 +194,7 @@ export const htmlTemplate = html`
         is="dom-repeat"
         items="[[_computePrimaryReviewers(change)]]"
         as="reviewer"
+        indexAs="index"
       >
         <gr-account-link
           hide-avatar=""
@@ -206,7 +204,11 @@ export const htmlTemplate = html`
           change="[[change]]"
           account="[[reviewer]]"
         ></gr-account-link
-        ><span class="lastChildHidden" aria-hidden="true">, </span>
+        ><span
+          hidden$="[[_computeCommaHidden(index, change)]]"
+          aria-hidden="true"
+          >,
+        </span>
       </template>
       <template is="dom-if" if="[[_computeAdditionalReviewersCount(change)]]">
         <span title="[[_computeAdditionalReviewersTitle(change, config)]]">