completion: fix completion after 'git --option <TAB>'

The bash completion doesn't work when certain options to git itself are
specified, e.g. 'git --no-pager <TAB>' errors out with

    error: invalid key: alias.--no-pager

The main _git() completion function finds out the git command name by
looping through all the words on the command line and searching for
the first word that is not a known option for the git command.

Unfortunately the list of known git options was not updated in a long
time, and newer options are not skipped but mistaken for a git command.
Such a misrecognized "command" is then passed to __git_aliased_command(),
which in turn passes it to a 'git config' query, hence the error.

Currently the following options are misrecognized for a git command:

  -c --no-pager --exec-path --html-path --man-path --info-path
  --no-replace-objects --work-tree= --namespace=

To fix this we could just update the list of options to be skipped,
but the same issue will likely arise, if the git command learns a new
option in the future.  Therefore, to make it more future proof against
new options, this patch changes that loop to skip all option-looking
words, i.e. words starting with a dash.

We also have to handle the '-c' option specially, because it takes a
configutation parameter in a separate word, which must be skipped,
too.

[fc: added tests]

Signed-off-by: SZEDER Gábor <[email protected]>
Signed-off-by: Felipe Contreras <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: szeder

contrib/completion/git-completion.bash

@@ -2623,8 +2623,9 @@ _git ()
 		case "$i" in
 		--git-dir=*) __git_dir="${i#--git-dir=}" ;;
 		--bare)      __git_dir="." ;;
-		--version|-p|--paginate) ;;
 		--help) command="help"; break ;;
+		-c) c=$((++c)) ;;
+		-*) ;;
 		*) command="$i"; break ;;
 		esac
 		((c++))

t/t9902-completion.sh

@@ -223,4 +223,21 @@ test_expect_success 'general options' '
 	test_completion "git --inf" "--info-path " &&
 	test_completion "git --no-r" "--no-replace-objects "
 '
+
+test_expect_success 'general options plus command' '
+	test_completion "git --version check" "checkout " &&
+	test_completion "git --paginate check" "checkout " &&
+	test_completion "git --git-dir=foo check" "checkout " &&
+	test_completion "git --bare check" "checkout " &&
+	test_completion "git --help des" "describe " &&
+	test_completion "git --exec-path=foo check" "checkout " &&
+	test_completion "git --html-path check" "checkout " &&
+	test_completion "git --no-pager check" "checkout " &&
+	test_completion "git --work-tree=foo check" "checkout " &&
+	test_completion "git --namespace=foo check" "checkout " &&
+	test_completion "git --paginate check" "checkout " &&
+	test_completion "git --info-path check" "checkout " &&
+	test_completion "git --no-replace-objects check" "checkout "
+'
+
 test_done