From da8763d88975299a0887ddeaeb01e6a6a0cc7fea Mon Sep 17 00:00:00 2001
From: Greg Price <greg@zulipchat.com>
Date: Fri, 30 Apr 2021 14:49:33 -0700
Subject: [PATCH] tools: Avoid `readlink -f` in *-pull-request scripts.

This is a feature of GNU readlink that isn't in the BSD readlink
found on macOS.

For using this and other GNU coreutils features in our scripts in
general, we could use a solution like mobile's tools/lib/ensure-coreutils.sh
to get GNU coreutils on the PATH -- check if it's there already,
if not then try to find a Homebrew install of it and use that, if not
then print a helpful message.

But even then there'd be a bootstrapping problem of how to find
ensure-coreutils.sh .  That involves exactly the same problem as we
have for finding git-tools.sh in these lines.  So in fact in mobile
for the task of finding ensure-coreutils.sh in the first place, we
do without `readlink -f` anyway.

The one consequence of this behavior-wise is that if you make a
symlink somewhere that points directly at that script (say in your
`~/bin/`), and try to run it using that symlink, it won't work.
(It'll still work just fine if there are symlinks somewhere higher
up in the paths involved -- just not for the script itself.)
An ideal CLI program really should support that, I think, but
lacking a better idea, this seems an acceptable compromise.
---
 tools/fetch-pull-request        | 4 ++--
 tools/fetch-rebase-pull-request | 4 ++--
 tools/reset-to-pull-request     | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/tools/fetch-pull-request b/tools/fetch-pull-request
index d23b34f774..0d6c4c961e 100755
--- a/tools/fetch-pull-request
+++ b/tools/fetch-pull-request
@@ -1,9 +1,9 @@
 #!/usr/bin/env bash
 set -e
 
-this_file=$(readlink -f "${BASH_SOURCE[0]}")
+this_dir=${BASH_SOURCE[0]%/*}
 # shellcheck source=lib/git-tools.bash
-. "${this_file%/*}"/lib/git-tools.bash
+. "${this_dir}"/lib/git-tools.bash
 
 require_clean_work_tree 'check out PR as branch'
 
diff --git a/tools/fetch-rebase-pull-request b/tools/fetch-rebase-pull-request
index 115f61d9d8..31ff4cdf75 100755
--- a/tools/fetch-rebase-pull-request
+++ b/tools/fetch-rebase-pull-request
@@ -1,9 +1,9 @@
 #!/usr/bin/env bash
 set -e
 
-this_file=$(readlink -f "${BASH_SOURCE[0]}")
+this_dir=${BASH_SOURCE[0]%/*}
 # shellcheck source=lib/git-tools.bash
-. "${this_file%/*}"/lib/git-tools.bash
+. "${this_dir}"/lib/git-tools.bash
 
 require_clean_work_tree 'check out PR as branch'
 
diff --git a/tools/reset-to-pull-request b/tools/reset-to-pull-request
index 0480d5535f..6e5962ac62 100755
--- a/tools/reset-to-pull-request
+++ b/tools/reset-to-pull-request
@@ -39,9 +39,9 @@ if [ -z "$request_id" ]; then
     usage
 fi
 
-this_file=$(readlink -f "${BASH_SOURCE[0]}")
+this_dir=${BASH_SOURCE[0]%/*}
 # shellcheck source=lib/git-tools.bash
-. "${this_file%/*}"/lib/git-tools.bash
+. "${this_dir}"/lib/git-tools.bash
 
 require_clean_work_tree 'reset to PR'