git-compat-util: add xstrdup_or_null helper

diff --git a/t/t4022-diff-rewrite.sh b/t/t4022-diff-rewrite.sh
index c00a94b9ba4498e72a31856aac9cf653bbce8ba3..2d030a4ec35009105c26e9689dcae1150fed7b2d 100755 (executable)
--- a/t/t4022-diff-rewrite.sh
+++ b/t/t4022-diff-rewrite.sh
@@ -66,5 +66,35 @@ test_expect_success 'suppress deletion diff with -B -D' '
        grep -v "Linus Torvalds" actual
 '
 
+test_expect_success 'prepare a file that ends with an incomplete line' '
+       test_seq 1 99 >seq &&
+       printf 100 >>seq &&
+       git add seq &&
+       git commit seq -m seq
+'
+
+test_expect_success 'rewrite the middle 90% of sequence file and terminate with newline' '
+       test_seq 1 5 >seq &&
+       test_seq 9331 9420 >>seq &&
+       test_seq 96 100 >>seq
+'
+
+test_expect_success 'confirm that sequence file is considered a rewrite' '
+       git diff -B seq >res &&
+       grep "dissimilarity index" res
+'
+
+test_expect_success 'no newline at eof is on its own line without -B' '
+       git diff seq >res &&
+       grep "^\\\\ " res &&
+       ! grep "^..*\\\\ " res
+'
+
+test_expect_success 'no newline at eof is on its own line with -B' '
+       git diff -B seq >res &&
+       grep "^\\\\ " res &&
+       ! grep "^..*\\\\ " res
+'
+
 test_done