This makes it possible to implement bash completion for add-on commands, that will work even when the bash completion scripts are being loaded on-demand, as is done by the bash-completion package.
git's bash completion handles subcommands by running a _git_$command function. As well as the many such functions included in git-completion.bash, there can be other functions defined elsewhere to support third-party add-on git commands, and they'll happily be used.
But, bash completion scripts are often loaded on demand, as shown in the completion_loader example in bash's man page, and the bash-completion implementation that is commonly used on many Linux systems. The demand loading will load this very script from some place like /usr/share/bash-completion/completions/git, when the user complete a git command. But, completion scripts for git add-on commands don't get loaded.
For example, when I wrote a git-annex bash completion script, bash was unable to tab complete "git annex foo", until I tab completed a "git-annex" command. Which loaded the git-annex completion, and then that same completion worked to make "git annex foo" tab complete. An inconsistent UI..
So, if the git completion script is unable to find the wanted _git_$command function, have it fall-back to looking for a git-$command completion script, and loading it. The add-on script is looked for in the same directory as the git completion script, which we can find by looking at BASH_SOURCE.
Signed-off-by: Joey Hess <joeyh@joeyh.name> --- contrib/completion/git-completion.bash | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
Show changes to contrib/completion/git-completion.bash +10 −1
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash index c97c648..ba91b2a 100644 --- a/contrib/completion/git-completion.bash +++ b/contrib/completion/git-completion.bash @@ -2614,7 +2614,16 @@ __git_main () if [ -n "$expansion" ]; then words[1]=$expansion completion_func="_git_${expansion//-/_}" - declare -f $completion_func >/dev/null && $completion_func + declare -f $completion_func >/dev/null && $completion_func && return + fi + + # As a fallback, if no completion function is defined for the + # command, look for add-on command completion script in same + # directory as this completion script, and if found, source it, + # and restart completion using it. + local compdir="${BASH_SOURCE%/*}" + if [ -e "$compdir/git-$command" ]; then + source "$compdir/git-$command" && __git_main "$@" fi }
-- 2.1.4