[PATCH 11/11] completion: complete remote branches for git switch --track

[Jacob Keller <jacob.e.keller@intel.com>]

From: Jacob Keller <jacob.keller@gmail.com>

git switch --track <remote>/<branch> will be interpreted as a DWIM to
create a local tracking branch named <branch> tracking the specified
remote.

Completion support for this case is buggy, because it will instead
report only local branches.

Fix this by extending __git_complete_refs with a new mode,
"remote-heads" which will list all reference under refs/remotes/*.

By doing this, "git switch --track <TAB>" changes from the rather
useless set of local branches to only listing remote branches.

Note that if the user has specified "-c" or "-C" already on the command
line, this will still enable completing all references, as the check to
use the mode "refs" occurs first in an if-elif chain.

This finally fixes the "git switch --track" test case, so it is updated
accordingly.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
---
 contrib/completion/git-completion.bash | 25 +++++++++++++++++++++++--
 t/t9902-completion.sh                  |  5 +----
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index f9be0dabb03e..cdd141b2ba1d 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -624,6 +624,19 @@ __git_heads ()
 			"refs/heads/$cur_*" "refs/heads/$cur_*/**"
 }
 
+# Lists branches from remote repositories.
+# 1: A prefix to be added to each listed branch (optional).
+# 2: List only branches matching this word (optional; list all branches if
+#    unset or empty).
+# 3: A suffix to be appended to each listed branch (optional).
+__git_remote_heads ()
+{
+	local pfx="${1-}" cur_="${2-}" sfx="${3-}"
+
+	__git for-each-ref --format="${pfx//\%/%%}%(refname:strip=2)$sfx" \
+			"refs/remotes/$cur_*" "refs/remotes/$cur_*/**"
+}
+
 # Lists tags from the local repository.
 # Accepts the same positional parameters as __git_heads() above.
 __git_tags ()
@@ -783,8 +796,9 @@ __git_refs ()
 # --sfx=<suffix>: A suffix to be appended to each ref instead of the default
 #                 space.
 # --mode=<mode>: What set of refs to complete, one of 'refs' (the default) to
-#                complete all refs, or 'heads' to complete only branches. Note
-#                that --remote is only compatible with --mode=refs.
+#                complete all refs, 'heads' to complete only branches, or
+#                'remote-heads' to complete only remote branches. Note that
+#                --remote is only compatible with --mode=refs.
 __git_complete_refs ()
 {
 	local remote dwim pfx cur_="$cur" sfx=" " mode="refs"
@@ -810,6 +824,8 @@ __git_complete_refs ()
 			__gitcomp_direct "$(__git_refs "$remote" "" "$pfx" "$cur_" "$sfx")" ;;
 		heads)
 			__gitcomp_direct "$(__git_heads "$pfx" "$cur_" "$sfx")" ;;
+		remote-heads)
+			__gitcomp_direct "$(__git_remote_heads "$pfx" "$cur_" "$sfx")" ;;
 		*)
 			return 1 ;;
 	esac
@@ -2299,8 +2315,13 @@ _git_switch ()
 		# local branches, or DWIM with remote branch names. However,
 		# certain options for creating branches or detaching should
 		# complete all references.
+		#
+		# Additionally, if --track is provided on its own, we should
+		# complete only remote branch names.
 		if [ -n "$(__git_find_on_cmdline "-d --detach -c -C")" ]; then
 			mode="refs"
+		elif [ -n "$(__git_find_on_cmdline "--track")" ]; then
+			mode="remote-heads"
 		fi
 
 		__git_complete_refs $dwim_opt --mode=$mode
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index 68296d79a3e9..7491d8c3b72d 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -1267,10 +1267,7 @@ test_expect_success 'git switch - with --detach, complete all references' '
 	EOF
 '
 
-# TODO: Since --track on its own will perform a DWIM to extract the local
-# branch name, we should complete only the remote branches with their remote
-# name.
-test_expect_failure 'git switch - with --track, complete only remote branches' '
+test_expect_success 'git switch - with --track, complete only remote branches' '
 	test_completion "git switch --track " <<-\EOF
 	other/branch-in-other Z
 	other/master-in-other Z
-- 
2.25.2