From 366ed7f972c74e6bcd6d2d14156c1b60350191bd Mon Sep 17 00:00:00 2001
From: Jim Graham <flar@google.com>
Date: Mon, 13 Jan 2025 15:49:03 -0800
Subject: [PATCH] Fix paths when running clang-tidy on git diffs (#161496)

The working directory was `engine/src/flutter` but all of the file names
already had those parent directories on them so we'd be trying to find
build commands for `engine/src/flutter/engine/src/flutter`. This change
tells the git commands to make the file names relative to the working
directory (which is already `engine/src/flutter`).

Someone more familiar with the `--lint-head` option should double check
its operation since I wasn't sure exactly what it was supposed to do,
but the list of files it generated looked correct.
---
 .../pkg/git_repo_tools/lib/git_repo_tools.dart      |  4 +++-
 .../git_repo_tools/test/git_repo_tools_test.dart    | 13 ++++++++-----
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/engine/src/flutter/tools/pkg/git_repo_tools/lib/git_repo_tools.dart b/engine/src/flutter/tools/pkg/git_repo_tools/lib/git_repo_tools.dart
index 34f5bd462d..47b7d74b07 100644
--- a/engine/src/flutter/tools/pkg/git_repo_tools/lib/git_repo_tools.dart
+++ b/engine/src/flutter/tools/pkg/git_repo_tools/lib/git_repo_tools.dart
@@ -86,7 +86,8 @@ final class GitRepo {
       'git',
       'diff',
       '--name-only',
-      '--diff-filter=ACMRT',
+      '--diff-filter=ACMRT', // Added, copied, modified, renamed, or type-changed.
+      '--relative', // _gitOutputToList will prepend the CWD so we don't want duplicate sub-paths
       mergeBase,
     ]);
     return _gitOutputToList(masterResult);
@@ -111,6 +112,7 @@ final class GitRepo {
       '--no-commit-id',
       '--name-only',
       '--diff-filter=ACMRT', // Added, copied, modified, renamed, or type-changed.
+      '--relative', // _gitOutputToList will prepend the CWD so we don't want duplicate sub-paths
       '-r',
       'HEAD',
     ]);
diff --git a/engine/src/flutter/tools/pkg/git_repo_tools/test/git_repo_tools_test.dart b/engine/src/flutter/tools/pkg/git_repo_tools/test/git_repo_tools_test.dart
index 7b17d9c46a..a5d4bbc508 100644
--- a/engine/src/flutter/tools/pkg/git_repo_tools/test/git_repo_tools_test.dart
+++ b/engine/src/flutter/tools/pkg/git_repo_tools/test/git_repo_tools_test.dart
@@ -26,7 +26,8 @@ void main() {
           }
 
           // Succeed calling "git diff --name-only --diff-filter=ACMRT fake-sha-hash".
-          if (command.join(' ') == 'git diff --name-only --diff-filter=ACMRT $fakeShaHash') {
+          if (command.join(' ') ==
+              'git diff --name-only --diff-filter=ACMRT --relative $fakeShaHash') {
             return FakeProcess(stdout: 'file1\nfile2');
           }
 
@@ -62,7 +63,8 @@ void main() {
             return FakeProcess();
           }
 
-          if (command.join(' ') == 'git diff --name-only --diff-filter=ACMRT $fakeShaHash') {
+          if (command.join(' ') ==
+              'git diff --name-only --diff-filter=ACMRT --relative $fakeShaHash') {
             return FakeProcess(stdout: 'file1\nfile2');
           }
 
@@ -91,7 +93,7 @@ void main() {
           }
 
           if (command.join(' ') ==
-              'git diff-tree --no-commit-id --name-only --diff-filter=ACMRT -r HEAD') {
+              'git diff-tree --no-commit-id --name-only --diff-filter=ACMRT --relative -r HEAD') {
             return FakeProcess(stdout: 'file1\nfile2');
           }
 
@@ -120,7 +122,7 @@ void main() {
           }
 
           if (command.join(' ') ==
-              'git diff-tree --no-commit-id --name-only --diff-filter=ACMRT -r HEAD') {
+              'git diff-tree --no-commit-id --name-only --diff-filter=ACMRT --relative -r HEAD') {
             return FakeProcess(stdout: 'file1\nfile2');
           }
 
@@ -164,7 +166,8 @@ void main() {
             return FakeProcess();
           }
 
-          if (command.join(' ') == 'git diff --name-only --diff-filter=ACMRT $fakeShaHash') {
+          if (command.join(' ') ==
+              'git diff --name-only --diff-filter=ACMRT --relative $fakeShaHash') {
             return FakeProcess(stdout: 'file1\nfile2');
           }