Improves diff stat parsing perf & memory usage

src/env/node/git/git.ts

@@ -557,6 +557,7 @@ export class Git {
 			'--name-status',
 			`-M${similarityThreshold == null ? '' : `${similarityThreshold}%`}`,
 			'--no-ext-diff',
+			'-z',
 		];
 		if (filters != null && filters.length !== 0) {
 			params.push(`--diff-filter=${filters.join('')}`);
@@ -1354,7 +1355,7 @@ export class Git {
 	}
 
 	show__name_status(repoPath: string, fileName: string, ref: string) {
-		return this.git<string>({ cwd: repoPath }, 'show', '--name-status', '--format=', ref, '--', fileName);
+		return this.git<string>({ cwd: repoPath }, 'show', '--name-status', '--format=', '-z', ref, '--', fileName);
 	}
 
 	show_ref__tags(repoPath: string) {

src/env/node/git/localGitProvider.ts

@@ -2029,6 +2029,8 @@ export class LocalGitProvider implements GitProvider, Disposable {
 				similarityThreshold: this.container.config.advanced.similarityThreshold,
 				...options,
 			});
+			if (!data) return undefined;
+
 			const files = GitDiffParser.parseNameStatus(data, repoPath);
 			return files == null || files.length === 0 ? undefined : files;
 		} catch (ex) {

src/git/parsers/diffParser.ts

@@ -3,9 +3,7 @@ import { getLines } from '../../system/string';
 import { GitDiff, GitDiffHunk, GitDiffHunkLine, GitDiffLine, GitDiffShortStat } from '../models/diff';
 import { GitFile, GitFileStatus } from '../models/file';
 
-const nameStatusDiffRegex = /^(.*?)\t(.*?)(?:\t(.*?))?$/gm;
-const shortStatDiffRegex =
-	/^\s*(\d+)\sfiles? changed(?:,\s+(\d+)\s+insertions?\(\+\))?(?:,\s+(\d+)\s+deletions?\(-\))?/;
+const shortStatDiffRegex = /(\d+)\s+files? changed(?:,\s+(\d+)\s+insertions?\(\+\))?(?:,\s+(\d+)\s+deletions?\(-\))?/;
 const unifiedDiffRegex = /^@@ -([\d]+)(?:,([\d]+))? \+([\d]+)(?:,([\d]+))? @@(?:.*?)\n([\s\S]*?)(?=^@@)/gm;
 
 export class GitDiffParser {
@@ -150,32 +148,22 @@ export class GitDiffParser {
 
 		const files: GitFile[] = [];
 
-		let status: string;
-		let fileName: string;
-		let originalFileName: string;
+		let status;
 
-		let match: RegExpExecArray | null;
-		do {
-			match = nameStatusDiffRegex.exec(data);
-			if (match == null) break;
-
-			[, status, fileName, originalFileName] = match;
+		const fields = data.split('\0');
+		for (let i = 0; i < fields.length - 1; i++) {
+			status = fields[i][0];
+			if (status === '.') {
+				status = '?';
+			}
 
 			files.push({
+				status: status as GitFileStatus,
+				path: fields[++i],
+				originalPath: status[0] === 'R' || status[0] === 'C' ? fields[++i] : undefined,
 				repoPath: repoPath,
-				status: (!status.startsWith('.') ? status[0].trim() : '?') as GitFileStatus,
-				conflictStatus: undefined,
-				indexStatus: undefined,
-				workingTreeStatus: undefined,
-				// Stops excessive memory usage -- https://bugs.chromium.org/p/v8/issues/detail?id=2869
-				path: ` ${fileName}`.substr(1),
-				// Stops excessive memory usage -- https://bugs.chromium.org/p/v8/issues/detail?id=2869
-				originalPath:
-					originalFileName == null || originalFileName.length === 0
-						? undefined
-						: ` ${originalFileName}`.substr(1),
 			});
-		} while (true);
+		}
 
 		return files;
 	}