feat(git-v8): preserve original author when backporting

components/git/v8.js

@@ -44,10 +44,22 @@ export function builder(yargs) {
             describe: 'Bump V8 embedder version number or patch version',
             default: true
           })
+          .option('gpg-sign', {
+            alias: 'S',
+            type: 'boolean',
+            describe: 'GPG-sign commits',
+            default: false
+          })
+          .option('preserve-original-author', {
+            type: 'boolean',
+            describe: 'Preserve original commit author and date',
+            default: true
+          })
           .option('squash', {
             type: 'boolean',
             describe:
-                'If multiple commits are backported, squash them into one',
+                'If multiple commits are backported, squash them into one. When ' +
+                '`--squash` is passed, `--preserve-original-author` will be ignored',
             default: false
           });
       }
@@ -88,7 +100,7 @@ export function handler(argv) {
       input,
       spawnArgs: {
         cwd: options.nodeDir,
-        stdio: input ? ['pipe', 'ignore', 'ignore'] : 'ignore'
+        stdio: input ? ['pipe', 'inherit', 'inherit'] : 'inherit'
       }
     });
   };
@@ -97,7 +109,7 @@ export function handler(argv) {
     return forceRunAsync('git', args, {
       ignoreFailure: false,
       captureStdout: true,
-      spawnArgs: { cwd: options.v8Dir, stdio: ['ignore', 'pipe', 'ignore'] }
+      spawnArgs: { cwd: options.v8Dir, stdio: ['ignore', 'pipe', 'inherit'] }
     });
   };
 

lib/update-v8/backport.js

@@ -9,6 +9,7 @@ import { ListrEnquirerPromptAdapter } from '@listr2/prompt-adapter-enquirer';
 import { shortSha } from '../utils.js';
 
 import { getCurrentV8Version } from './common.js';
+import { forceRunAsync } from '../run.js';
 
 export async function checkOptions(options) {
   if (options.sha.length > 1 && options.squash) {
@@ -41,6 +42,8 @@ export function doBackport(options) {
       }
     }
     todo.push(commitSquashedBackport());
+  } else if (options.preserveOriginalAuthor) {
+    todo.push(cherryPickV8Commits(options));
   } else {
     todo.push(applyAndCommitPatches());
   }
@@ -76,18 +79,47 @@ function commitSquashedBackport() {
   };
 };
 
-function commitPatch(patch) {
+const commitTask = (patch, extraArgs, trailers) => async(ctx) => {
+  const messageTitle = formatMessageTitle([patch]);
+  const messageBody = formatMessageBody(patch, false, trailers);
+  await ctx.execGitNode('add', ['deps/v8']);
+  await ctx.execGitNode('commit', [
+    ...ctx.gpgSign, ...extraArgs,
+    '-m', messageTitle, '-m', messageBody
+  ]);
+};
+
+function amendHEAD(patch) {
   return {
-    title: 'Commit patch',
+    title: 'Amend/commit',
     task: async(ctx) => {
-      const messageTitle = formatMessageTitle([patch]);
-      const messageBody = formatMessageBody(patch, false);
-      await ctx.execGitNode('add', ['deps/v8']);
-      await ctx.execGitNode('commit', ['-m', messageTitle, '-m', messageBody]);
+      let coAuthor;
+      if (patch.hadConflicts) {
+        const getGitConfigEntry = async(configKey) => {
+          const output = await forceRunAsync('git', ['config', configKey], {
+            ignoreFailure: false,
+            captureStdout: true,
+            spawnArgs: { cwd: ctx.nodeDir }
+          });
+          return output.trim();
+        };
+        await ctx.execGitNode('am', [...ctx.gpgSign, '--continue']);
+        coAuthor = `\nCo-authored-by: ${
+          await getGitConfigEntry('user.name')} <${
+          await getGitConfigEntry('user.email')}>`;
+      }
+      await commitTask(patch, ['--amend'], coAuthor)(ctx);
     }
   };
 }
 
+function commitPatch(patch) {
+  return {
+    title: 'Commit patch',
+    task: commitTask(patch)
+  };
+}
+
 function formatMessageTitle(patches) {
   const action =
     patches.some(patch => patch.hadConflicts) ? 'backport' : 'cherry-pick';
@@ -106,12 +138,12 @@ function formatMessageTitle(patches) {
   }
 }
 
-function formatMessageBody(patch, prefixTitle) {
+function formatMessageBody(patch, prefixTitle, trailers = '') {
   const indentedMessage = patch.message.replace(/\n/g, '\n    ');
   const body =
     'Original commit message:\n\n' +
     `    ${indentedMessage}\n\n` +
-    `Refs: https://github.com/v8/v8/commit/${patch.sha}`;
+    `Refs: https://github.com/v8/v8/commit/${patch.sha}${trailers}`;
 
   if (prefixTitle) {
     const action = patch.hadConflicts ? 'Backport' : 'Cherry-pick';
@@ -167,6 +199,15 @@ function applyAndCommitPatches() {
   };
 }
 
+function cherryPickV8Commits() {
+  return {
+    title: 'Cherry-pick commit from V8 clone to deps/v8',
+    task: (ctx, task) => {
+      return task.newListr(ctx.patches.map(cherryPickV8CommitTask));
+    }
+  };
+}
+
 function applyPatchTask(patch) {
   return {
     title: `Commit ${shortSha(patch.sha)}`,
@@ -190,10 +231,33 @@ function applyPatchTask(patch) {
   };
 }
 
-async function applyPatch(ctx, task, patch) {
+function cherryPickV8CommitTask(patch) {
+  return {
+    title: `Commit ${shortSha(patch.sha)}`,
+    task: (ctx, task) => {
+      const todo = [
+        {
+          title: 'Cherry-pick',
+          task: (ctx, task) => applyPatch(ctx, task, patch, 'am')
+        }
+      ];
+      if (ctx.bump !== false) {
+        if (ctx.nodeMajorVersion < 9) {
+          todo.push(incrementV8Version());
+        } else {
+          todo.push(incrementEmbedderVersion());
+        }
+      }
+      todo.push(amendHEAD(patch));
+      return task.newListr(todo);
+    }
+  };
+}
+
+async function applyPatch(ctx, task, patch, method = 'apply') {
   try {
     await ctx.execGitNode(
-      'apply',
+      method,
       ['-p1', '--3way', '--directory=deps/v8'],
       patch.data /* input */
     );

lib/update-v8/index.js

@@ -26,6 +26,7 @@ export function minor(options) {
 export async function backport(options) {
   const shouldStop = await checkOptions(options);
   if (shouldStop) return;
+  options.gpgSign = options.gpgSign ? ['-S'] : [];
   const tasks = new Listr(
     [updateV8Clone(), doBackport(options)],
     getOptions(options)