completion: list paths and refs for 'git worktree add'

Complete paths after 'git worktree add <TAB>' and refs after 'git
worktree add -b <TAB>' and 'git worktree add some/dir <TAB>'.

Uncharacteristically for a Git command, 'git worktree add' takes a
mandatory path parameter before a commit-ish as its optional last
parameter.  In addition, it has both standalone --options and options
with a mandatory unstuck parameter ('-b <new-branch>').  Consequently,
trying to complete refs for that last optional commit-ish parameter
resulted in a more convoluted than usual completion function, but
hopefully all the included comments will make it not too hard to
digest.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 90284e5954ab65fafa4ea716831e31fe4028c4be..1771e4681357cccdac47c000baf9e12099c9ac76 100644 (file)
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -3011,6 +3011,42 @@ _git_worktree ()
        *,--*)
                __gitcomp_builtin worktree_$subcommand
                ;;
+       add,*)  # usage: git worktree add [<options>] <path> [<commit-ish>]
+               # Here we are not completing an --option, it's either the
+               # path or a ref.
+               case "$prev" in
+               -b|-B)  # Complete refs for branch to be created/reseted.
+                       __git_complete_refs
+                       ;;
+               -*)     # The previous word is an -o|--option without an
+                       # unstuck argument: have to complete the path for
+                       # the new worktree, so don't list anything, but let
+                       # Bash fall back to filename completion.
+                       ;;
+               *)      # The previous word is not an --option, so it must
+                       # be either the 'add' subcommand, the unstuck
+                       # argument of an option (e.g. branch for -b|-B), or
+                       # the path for the new worktree.
+                       if [ $cword -eq $((subcommand_idx+1)) ]; then
+                               # Right after the 'add' subcommand: have to
+                               # complete the path, so fall back to Bash
+                               # filename completion.
+                               :
+                       else
+                               case "${words[cword-2]}" in
+                               -b|-B)  # After '-b <branch>': have to
+                                       # complete the path, so fall back
+                                       # to Bash filename completion.
+                                       ;;
+                               *)      # After the path: have to complete
+                                       # the ref to be checked out.
+                                       __git_complete_refs
+                                       ;;
+                               esac
+                       fi
+                       ;;
+               esac
+               ;;
        lock,*|remove,*|unlock,*)
                __git_complete_worktree_paths
                ;;