Merge branch 'as/check-ignore'

"git check-ignore ." segfaulted, as a function it calls deep in its
callchain took a string in the <ptr, length> form but did not stop
when given an empty string.

* as/check-ignore:
  name-hash: allow hashing an empty string
  t0008: document test_expect_success_multi

builtin/check-ignore.c

@@ -89,7 +89,7 @@ static int check_ignore(const char *prefix, const char **pathspec)
 					? strlen(prefix) : 0, path);
 		full_path = check_path_for_gitlink(full_path);
 		die_if_path_beyond_symlink(full_path, prefix);
-		if (!seen[i] && path[0]) {
+		if (!seen[i]) {
 			exclude = last_exclude_matching_path(&check, full_path,
 							     -1, &dtype);
 			if (exclude) {

name-hash.c

@@ -24,11 +24,11 @@ static unsigned int hash_name(const char *name, int namelen)
 {
 	unsigned int hash = 0x123;
 
-	do {
+	while (namelen--) {
 		unsigned char c = *name++;
 		c = icase_hash(c);
 		hash = hash*101 + c;
-	} while (--namelen);
+	}
 	return hash;
 }
 

t/t0008-ignores.sh

@@ -75,6 +75,16 @@ test_check_ignore () {
 	stderr_empty_on_success "$expect_code"
 }
 
+# Runs the same code with 3 different levels of output verbosity,
+# expecting success each time.  Takes advantage of the fact that
+# check-ignore --verbose output is the same as normal output except
+# for the extra first column.
+#
+# Arguments:
+#   - (optional) prereqs for this test, e.g. 'SYMLINKS'
+#   - test name
+#   - output to expect from -v / --verbose mode
+#   - code to run (should invoke test_check_ignore)
 test_expect_success_multi () {
 	prereq=
 	if test $# -eq 4
@@ -128,6 +138,7 @@ test_expect_success 'setup' '
 	cat <<-\EOF >.gitignore &&
 		one
 		ignored-*
+		top-level-dir/
 	EOF
 	for dir in . a
 	do
@@ -167,6 +178,10 @@ test_expect_success 'setup' '
 #
 # test invalid inputs
 
+test_expect_success_multi '. corner-case' '' '
+	test_check_ignore . 1
+'
+
 test_expect_success_multi 'empty command line' '' '
 	test_check_ignore "" 128 &&
 	stderr_contains "fatal: no path specified"