From 129d51fa0936c9bae48fadf3a3f39e26d69d24da Mon Sep 17 00:00:00 2001
From: Alex Vandiver <alexmv@dropbox.com>
Date: Thu, 18 May 2017 12:09:44 -0400
Subject: [PATCH] If the base commit for `arc patch` does not exist locally,
 try to fetch it

Summary:
If the commit does not exist locally, aborting still leaves
the user checked out on the branch.  In nearly all cases, all that is
necessary is a fetch -- but the branch must also be cleaned up.  This
leads to the pattern of:
```
arc patch D12345
[...base commit does not exist...]
^C
git checkout master
git branch -D arcpatch-D12345
git fetch
arc patch D12345
```

Solve this common problem by simply trying to fetch once if the commit does not
exist locally.

Test Plan: Ran `arc patch` on a recent diff.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D17949
---
 src/workflow/ArcanistPatchWorkflow.php | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/workflow/ArcanistPatchWorkflow.php b/src/workflow/ArcanistPatchWorkflow.php
index c1a8f878..227b020f 100644
--- a/src/workflow/ArcanistPatchWorkflow.php
+++ b/src/workflow/ArcanistPatchWorkflow.php
@@ -430,6 +430,18 @@ EOTEXT
     $repository_api = $this->getRepositoryAPI();
     $has_base_revision = $repository_api->hasLocalCommit(
       $bundle->getBaseRevision());
+    if (!$has_base_revision) {
+      if ($repository_api instanceof ArcanistGitAPI) {
+        echo phutil_console_format(
+          "<bg:blue>** %s **</bg> %s\n",
+          pht('INFO'),
+          pht('Base commit is not in local repository; trying to fetch.'));
+        $repository_api->execManualLocal('fetch --quiet --all');
+        $has_base_revision = $repository_api->hasLocalCommit(
+          $bundle->getBaseRevision());
+      }
+    }
+
     if ($this->canBranch() &&
          ($this->shouldBranch() ||
          ($this->shouldCommit() && $has_base_revision))) {