Teach bash about completing arguments for git-tag

Lately I have been doing a lot of calls to `git tag -d` and also to
`git tag -v`.  In both such cases being able to complete the names
of existing tags saves the fingers some typing effort.  We now look
for the -d or -v option to git-tag in the bash completion support
and offer up existing tag names as possible choices for these.

When creating a new tag we now also offer bash completion support
for the second argument to git-tag (the object to be tagged) as this
can often be a specific existing branch name and is not necessarily
the current HEAD.

If the -f option is being used to recreate an existing tag we now
also offer completion support on the existing tag names for the
first argument of git-tag, helping to the user to reselect the
prior tag name that they are trying to replace.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 5ed18215fdefe1c4864ae5c6f01a86a9ff36d012..cad842af4548f24041aba785f1629081e586e7c5 100755 (executable)
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -114,6 +114,27 @@ __git_heads ()
        done
 }
 
+__git_tags ()
+{
+       local cmd i is_hash=y dir="$(__gitdir "$1")"
+       if [ -d "$dir" ]; then
+               for i in $(git --git-dir="$dir" \
+                       for-each-ref --format='%(refname)' \
+                       refs/tags ); do
+                       echo "${i#refs/tags/}"
+               done
+               return
+       fi
+       for i in $(git-ls-remote "$1" 2>/dev/null); do
+               case "$is_hash,$i" in
+               y,*) is_hash=n ;;
+               n,*^{}) is_hash=y ;;
+               n,refs/tags/*) is_hash=y; echo "${i#refs/tags/}" ;;
+               n,*) is_hash=y; echo "$i" ;;
+               esac
+       done
+}
+
 __git_refs ()
 {
        local cmd i is_hash=y dir="$(__gitdir "$1")"
@@ -1050,6 +1071,40 @@ _git_submodule ()
        fi
 }
 
+_git_tag ()
+{
+       local i c=1 f=0
+       while [ $c -lt $COMP_CWORD ]; do
+               i="${COMP_WORDS[c]}"
+               case "$i" in
+               -d|-v)
+                       __gitcomp "$(__git_tags)"
+                       return
+                       ;;
+               -f)
+                       f=1
+                       ;;
+               esac
+               c=$((++c))
+       done
+
+       case "${COMP_WORDS[COMP_CWORD-1]}" in
+       -m|-F)
+               COMPREPLY=()
+               ;;
+       -*|tag|git-tag)
+               if [ $f = 1 ]; then
+                       __gitcomp "$(__git_tags)"
+               else
+                       COMPREPLY=()
+               fi
+               ;;
+       *)
+               __gitcomp "$(__git_refs)"
+               ;;
+       esac
+}
+
 _git ()
 {
        local i c=1 command __git_dir
@@ -1117,6 +1172,7 @@ _git ()
        show-branch) _git_log ;;
        stash)       _git_stash ;;
        submodule)   _git_submodule ;;
+       tag)         _git_tag ;;
        whatchanged) _git_log ;;
        *)           COMPREPLY=() ;;
        esac
@@ -1167,6 +1223,7 @@ complete -o default -o nospace -F _git_show git-show
 complete -o default -o nospace -F _git_stash git-stash
 complete -o default -o nospace -F _git_submodule git-submodule
 complete -o default -o nospace -F _git_log git-show-branch
+complete -o default -o nospace -F _git_tag git-tag
 complete -o default -o nospace -F _git_log git-whatchanged
 
 # The following are necessary only for Cygwin, and only are needed
@@ -1192,5 +1249,6 @@ complete -o default -o nospace -F _git_config git-config
 complete -o default -o nospace -F _git_shortlog git-shortlog.exe
 complete -o default -o nospace -F _git_show git-show.exe
 complete -o default -o nospace -F _git_log git-show-branch.exe
+complete -o default -o nospace -F _git_tag git-tag.exe
 complete -o default -o nospace -F _git_log git-whatchanged.exe
 fi