Merge branch 'ap/maint-diff-rename-avoid-overlap' into maint

* ap/maint-diff-rename-avoid-overlap:
tests: make sure rename pretty print works
diff: prevent pprint_rename from underrunning input
diff: Fix rename pretty-print when suffix and prefix overlap

diff --git a/diff.c b/diff.c
index 052974eb9729cca92c9e86be6e71f46052bcb788..db952a5bc71ac967cb045bada8c71f5fda218ca2 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -1264,6 +1264,7 @@ static char *pprint_rename(const char *a, const char *b)
        const char *new = b;
        struct strbuf name = STRBUF_INIT;
        int pfx_length, sfx_length;
+       int pfx_adjust_for_slash;
        int len_a = strlen(a);
        int len_b = strlen(b);
        int a_midlen, b_midlen;
@@ -1290,7 +1291,18 @@ static char *pprint_rename(const char *a, const char *b)
        old = a + len_a;
        new = b + len_b;
        sfx_length = 0;
-       while (a <= old && b <= new && *old == *new) {
+       /*
+        * If there is a common prefix, it must end in a slash.  In
+        * that case we let this loop run 1 into the prefix to see the
+        * same slash.
+        *
+        * If there is no common prefix, we cannot do this as it would
+        * underrun the input strings.
+        */
+       pfx_adjust_for_slash = (pfx_length ? 1 : 0);
+       while (a + pfx_length - pfx_adjust_for_slash <= old &&
+              b + pfx_length - pfx_adjust_for_slash <= new &&
+              *old == *new) {
                if (*old == '/')
                        sfx_length = len_a - (old - a);
                old--;

diff --git a/t/t4001-diff-rename.sh b/t/t4001-diff-rename.sh
index 844277cfa605f51cccd5d78a48a83fb75c03af9b..2f327b749588af7eda57187cba4d365233a25ef9 100755 (executable)
--- a/t/t4001-diff-rename.sh
+++ b/t/t4001-diff-rename.sh
@@ -102,4 +102,58 @@ test_expect_success 'setup for many rename source candidates' '
        grep warning actual.err
 '
 
+test_expect_success 'rename pretty print with nothing in common' '
+       mkdir -p a/b/ &&
+       : >a/b/c &&
+       git add a/b/c &&
+       git commit -m "create a/b/c" &&
+       mkdir -p c/b/ &&
+       git mv a/b/c c/b/a &&
+       git commit -m "a/b/c -> c/b/a" &&
+       git diff -M --summary HEAD^ HEAD >output &&
+       test_i18ngrep " a/b/c => c/b/a " output &&
+       git diff -M --stat HEAD^ HEAD >output &&
+       test_i18ngrep " a/b/c => c/b/a " output
+'
+
+test_expect_success 'rename pretty print with common prefix' '
+       mkdir -p c/d &&
+       git mv c/b/a c/d/e &&
+       git commit -m "c/b/a -> c/d/e" &&
+       git diff -M --summary HEAD^ HEAD >output &&
+       test_i18ngrep " c/{b/a => d/e} " output &&
+       git diff -M --stat HEAD^ HEAD >output &&
+       test_i18ngrep " c/{b/a => d/e} " output
+'
+
+test_expect_success 'rename pretty print with common suffix' '
+       mkdir d &&
+       git mv c/d/e d/e &&
+       git commit -m "c/d/e -> d/e" &&
+       git diff -M --summary HEAD^ HEAD >output &&
+       test_i18ngrep " {c/d => d}/e " output &&
+       git diff -M --stat HEAD^ HEAD >output &&
+       test_i18ngrep " {c/d => d}/e " output
+'
+
+test_expect_success 'rename pretty print with common prefix and suffix' '
+       mkdir d/f &&
+       git mv d/e d/f/e &&
+       git commit -m "d/e -> d/f/e" &&
+       git diff -M --summary HEAD^ HEAD >output &&
+       test_i18ngrep " d/{ => f}/e " output &&
+       git diff -M --stat HEAD^ HEAD >output &&
+       test_i18ngrep " d/{ => f}/e " output
+'
+
+test_expect_success 'rename pretty print common prefix and suffix overlap' '
+       mkdir d/f/f &&
+       git mv d/f/e d/f/f/e &&
+       git commit -m "d/f/e d/f/f/e" &&
+       git diff -M --summary HEAD^ HEAD >output &&
+       test_i18ngrep " d/f/{ => f}/e " output &&
+       git diff -M --stat HEAD^ HEAD >output &&
+       test_i18ngrep " d/f/{ => f}/e " output
+'
+
 test_done