[RFC PATCH] bash completion: complete refs for git-grep

Attempt ref completion once we have seen a regular expression, to help
the user with entering the <treeish> arguments.

Signed-off-by: Thomas Rast <redacted>
---

The use-case for this is actually a bit protracted but came up on IRC
yesterday: pasky asked if there was a simple way to grep through a
certain file in all refs.

Turns out git-grep already has half the required support: when given a
series of refs, it prefixes the matches with the ref, so the output is
already in a useful format.

Sadly it does not appear to support --all, --branches or similar
(which would be material for a separate patch).  But bash completion
can step in here: with M-*, it can expand all possible completions for
the current word onto the command line.

This is still RFC because, as you can see in the code below, I tried
to avoid completing at all while the user still needs to supply a
regex.  Sadly, bash turns the COMPREPLY=() into filename completion
anyway.  Is there a way to prevent this?  Otherwise the regex
complication should probably just go away and we can complete refs
always.


 contrib/completion/git-completion.bash |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 6fd7e1d..c8cced6 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash

@@ -1048,6 +1048,24 @@ _git_grep ()
 		return
 		;;
 	esac
+
+	local i c=1 have_regex=""
+	while [ $c -lt $COMP_CWORD ]; do
+		i="${COMP_WORDS[c]}"
+		case "$i" in
+		-e) ;;
+		-e*) have_regex="$c" ; break ;;
+		-*) ;;
+		*) have_regex="$c"; break ;;
+		esac
+		c=$((++c))
+	done
+
+	if [ -n "$have_regex" ]; then
+		__gitcomp "$(__git_refs)"
+		return
+	fi
+
 	COMPREPLY=()
 }
 

-- 
1.6.5.rc2.251.g34f85