config: add '--name-only' option to list only variable names

'git config' can only show values or name-value pairs, so if a shell
script needs the names of set config variables it has to run 'git config
--list' or '--get-regexp' and parse the output to separate config
variable names from their values.  However, such a parsing can't cope
with multi-line values.  Though 'git config' can produce null-terminated
output for newline-safe parsing, that's of no use in such a case, becase
shells can't cope with null characters.

Even our own bash completion script suffers from these issues.

Help the completion script, and shell scripts in general, by introducing
the '--name-only' option to modify the output of '--list' and
'--get-regexp' to list only the names of config variables, so they don't
have to perform error-prone post processing to separate variable names
from their values anymore.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/t/t1300-repo-config.sh b/t/t1300-repo-config.sh
index 66dd28644..52678e7d0 100755
--- a/t/t1300-repo-config.sh
+++ b/t/t1300-repo-config.sh
@@ -353,6 +353,18 @@ test_expect_success '--list without repo produces empty output' '
 '
 
 cat > expect << EOF
+beta.noindent
+nextsection.nonewline
+123456.a123
+version.1.2.3eX.alpha
+EOF
+
+test_expect_success '--name-only --list' '
+	git config --name-only --list >output &&
+	test_cmp expect output
+'
+
+cat > expect << EOF
 beta.noindent sillyValue
 nextsection.nonewline wow2 for me
 EOF
@@ -363,6 +375,16 @@ test_expect_success '--get-regexp' '
 '
 
 cat > expect << EOF
+beta.noindent
+nextsection.nonewline
+EOF
+
+test_expect_success '--name-only --get-regexp' '
+	git config --name-only --get-regexp in >output &&
+	test_cmp expect output
+'
+
+cat > expect << EOF
 wow2 for me
 wow4 for you
 EOF