Fix disappearing commenting ranges (#6069)

Author: alexr00

src/common/diffPositionMapping.ts

@@ -31,7 +31,7 @@ export function getDiffLineByPosition(diffHunks: DiffHunk[], diffLineNumber: num
 	return undefined;
 }
 
-export function mapOldPositionToNew(patch: string, line: number): number {
+export function mapOldPositionToNew(patch: string, line: number, documentLineCount?: number): number {
 	const diffReader = parseDiffHunk(patch);
 	let diffIter = diffReader.next();
 
@@ -43,6 +43,10 @@ export function mapOldPositionToNew(patch: string, line: number): number {
 			// No-op
 		} else if (diffHunk.oldLineNumber + diffHunk.oldLength - 1 < line) {
 			delta += diffHunk.newLength - diffHunk.oldLength;
+		} else if (documentLineCount === diffHunk.newLength) {
+			// The diff doesn't give us enough information to do a good calculation as entire document was added or removed
+			delta += diffHunk.newLength - diffHunk.oldLength;
+			return line + delta;
 		} else {
 			// Part of the hunk is before line, part is after.
 			for (const diffLine of diffHunk.diffLines) {

src/view/reviewCommentController.ts

@@ -479,8 +479,8 @@ export class ReviewCommentController extends CommentControllerBase
 
 				for (let i = 0; i < diffHunks.length; i++) {
 					const diffHunk = diffHunks[i];
-					const start = mapOldPositionToNew(contentDiff, diffHunk.newLineNumber);
-					const end = mapOldPositionToNew(contentDiff, diffHunk.newLineNumber + diffHunk.newLength - 1);
+					const start = mapOldPositionToNew(contentDiff, diffHunk.newLineNumber, document.lineCount);
+					const end = mapOldPositionToNew(contentDiff, diffHunk.newLineNumber + diffHunk.newLength - 1, document.lineCount);
 					if (start > 0 && end > 0) {
 						ranges.push(new vscode.Range(start - 1, 0, end - 1, 0));
 					}
@@ -514,7 +514,7 @@ export class ReviewCommentController extends CommentControllerBase
 		}
 
 		try {
-			if (matchedEditor && matchedEditor.document.isDirty) {
+			if (matchedEditor && matchedEditor.document.isDirty && vscode.workspace.getConfiguration('files', matchedEditor.document.uri).get('autoSave') !== 'afterDelay') {
 				const documentText = matchedEditor.document.getText();
 				const details = await this._repository.getObjectDetails(
 					this._folderRepoManager.activePullRequest.head.sha,