completion: add helper to count path components

A follow-up commit will use this with for-each-ref to strip the right
number of path components from refnames.

Signed-off-by: David Mandelberg <david@mandelberg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 37 insertions, 0 deletions

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 413911be3b..5fdc71208e 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -234,6 +234,17 @@ __git_dequote ()
 	done
 }
 
+# Prints the number of slash-separated components in a path.
+# 1: Path to count components of.
+__git_count_path_components ()
+{
+	local path="$1"
+	local relative="${path#/}"
+	relative="${relative%/}"
+	local slashes="/${relative//[^\/]}"
+	echo "${#slashes}"
+}
+
 # The following function is based on code from:
 #
 #   bash_completion - programmable completion functions for bash 3.2+
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index 51bd750837..015289c776 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -455,6 +455,32 @@ test_expect_success '__git_dequote - open double quote' '
 '
 
 
+test_expect_success '__git_count_path_components - no slashes' '
+	echo 1 >expected &&
+	__git_count_path_components a >"$actual" &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_count_path_components - relative' '
+	echo 3 >expected &&
+	__git_count_path_components a/b/c >"$actual" &&
+	test_cmp expected "$actual"
+
+'
+
+test_expect_success '__git_count_path_components - absolute' '
+	echo 3 >expected &&
+	__git_count_path_components /a/b/c >"$actual" &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_count_path_components - trailing slash' '
+	echo 3 >expected &&
+	__git_count_path_components a/b/c/ >"$actual" &&
+	test_cmp expected "$actual"
+'
+
+
 test_expect_success '__gitcomp_direct - puts everything into COMPREPLY as-is' '
 	sed -e "s/Z$//g" >expected <<-EOF &&
 	with-trailing-space Z