merge base for review manager.

Author: rebornix

src/view/reviewManager.ts

@@ -393,9 +393,10 @@ export class ReviewManager implements vscode.DecorationProvider {
 
 			const data = await this._prManager.getPullRequestChangedFiles(pr);
 			await this._prManager.fullfillPullRequestCommitInfo(pr);
-			let baseSha = pr.base.sha;
 			let headSha = pr.head.sha;
-			const contentChanges = await parseDiff(data, this._repository, baseSha);
+			let mergeBase = await this._prManager.getPullRequestMergeBase(pr);
+
+			const contentChanges = await parseDiff(data, this._repository, mergeBase);
 			this._localFileChanges = contentChanges.map(change => {
 				if (change instanceof SlimFileChange) {
 					return new RemoteFileChangeNode(

src/view/treeNodes/pullRequestNode.ts

@@ -138,7 +138,7 @@ export class PRNode extends TreeNode {
 			const data = await this._prManager.getPullRequestChangedFiles(this.pullRequestModel);
 			await this._prManager.fullfillPullRequestCommitInfo(this.pullRequestModel);
 			let mergeBase = await this._prManager.getPullRequestMergeBase(this.pullRequestModel);
-			const rawChanges = await parseDiff(data, this.repository, mergeBase || this.pullRequestModel.base.sha);
+			const rawChanges = await parseDiff(data, this.repository, mergeBase);
 			this._contentChanges = rawChanges.map(change => {
 				if (change instanceof SlimFileChange) {
 					return new RemoteFileChangeNode(