Refuse to expand skip groups with WHOLE_FILE

Skip groups should always be collapsed,
even if user preferences define file to be
automatically expanded.

Change-Id: I3eeb4b3a3eef13a403c911c941511a31046bc41f
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-processor/gr-diff-processor.ts b/polygerrit-ui/app/elements/diff/gr-diff-processor/gr-diff-processor.ts
index 08ea1a6..ab7ab8a 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-processor/gr-diff-processor.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-processor/gr-diff-processor.ts
@@ -307,8 +307,10 @@
       state.lineNums.right + 1
     );
 
-    if (this.context !== WHOLE_FILE) {
-      const hiddenStart = state.chunkIndex === 0 ? 0 : this.context;
+    const hasSkippedGroup = !!groups.find(g => g.skip);
+    if (this.context !== WHOLE_FILE || hasSkippedGroup) {
+      const contextNumLines = this.context > 0 ? this.context : 0;
+      const hiddenStart = state.chunkIndex === 0 ? 0 : contextNumLines;
       const hiddenEnd =
         lineCount -
         (firstUncollapsibleChunkIndex === chunks.length ? 0 : this.context);