t4073: add test for diffstat paths length when containing UTF-8 chars

Add test checking the length of filepaths containing UTF-8 chars when
generating a diffstat with various `name-width`s.

Signed-off-by: LorenzoPegorari <lorenzo.pegorari2002@gmail.com>
[jc: fixed up t/meson.build to spell the name of the new test file correctly]
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: LorenzoPegorari

t/meson.build

@@ -496,6 +496,7 @@ integration_tests = [
   't4070-diff-pairs.sh',
   't4071-diff-minimal.sh',
   't4072-diff-max-depth.sh',
+  't4073-diff-stat-name-width.sh',
   't4100-apply-stat.sh',
   't4101-apply-nonl.sh',
   't4102-apply-rename.sh',

t/t4073-diff-stat-name-width.sh

@@ -0,0 +1,61 @@
+#!/bin/sh
+
+test_description='git-diff check diffstat filepaths length when containing UTF-8 chars'
+
+. ./test-lib.sh
+
+
+create_files () {
+	mkdir -p "d你好" &&
+	touch "d你好/f再见"
+}
+
+test_expect_success 'setup' '
+	git init &&
+	git config core.quotepath off &&
+	git commit -m "Initial commit" --allow-empty &&
+	create_files &&
+	git add . &&
+	git commit -m "Added files"
+'
+
+test_expect_success 'test name-width long enough for filepath' '
+	git diff HEAD~1 HEAD --stat --stat-name-width=12 >out &&
+	grep "d你好/f再见 |" out &&
+	git diff HEAD~1 HEAD --stat --stat-name-width=11 >out &&
+	grep "d你好/f再见 |" out
+'
+
+test_expect_success 'test name-width not long enough for dir name' '
+	git diff HEAD~1 HEAD --stat --stat-name-width=10 >out &&
+	grep ".../f再见  |" out &&
+	git diff HEAD~1 HEAD --stat --stat-name-width=9 >out &&
+	grep ".../f再见 |" out
+'
+
+test_expect_success 'test name-width not long enough for slash' '
+	git diff HEAD~1 HEAD --stat --stat-name-width=8 >out &&
+	grep "...f再见 |" out
+'
+
+test_expect_success 'test name-width not long enough for file name' '
+	git diff HEAD~1 HEAD --stat --stat-name-width=7 >out &&
+	grep "...再见 |" out &&
+	git diff HEAD~1 HEAD --stat --stat-name-width=6 >out &&
+	grep "...见  |" out &&
+	git diff HEAD~1 HEAD --stat --stat-name-width=5 >out &&
+	grep "...见 |" out &&
+	git diff HEAD~1 HEAD --stat --stat-name-width=4 >out &&
+	grep "...  |" out
+'
+
+test_expect_success 'test name-width minimum length' '
+	git diff HEAD~1 HEAD --stat --stat-name-width=3 >out &&
+	grep "... |" out &&
+	git diff HEAD~1 HEAD --stat --stat-name-width=2 >out &&
+	grep "... |" out &&
+	git diff HEAD~1 HEAD --stat --stat-name-width=1 >out &&
+	grep "... |" out
+'
+
+test_done