Merge branch 'js/diff-ni'

* js/diff-ni:
  Get rid of the dependency to GNU diff in the tests
  diff --no-index: support /dev/null as filename
  diff-ni: fix the diff with standard input
  diff: support reading a file from stdin via "-"

diff.c

@@ -1364,6 +1364,32 @@ static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 	return e;
 }
 
+static int populate_from_stdin(struct diff_filespec *s)
+{
+#define INCREMENT 1024
+	char *buf;
+	unsigned long size;
+	int got;
+
+	size = 0;
+	buf = NULL;
+	while (1) {
+		buf = xrealloc(buf, size + INCREMENT);
+		got = xread(0, buf + size, INCREMENT);
+		if (!got)
+			break; /* EOF */
+		if (got < 0)
+			return error("error while reading from stdin %s",
+				     strerror(errno));
+		size += got;
+	}
+	s->should_munmap = 0;
+	s->data = buf;
+	s->size = size;
+	s->should_free = 1;
+	return 0;
+}
+
 /*
  * While doing rename detection and pickaxe operation, we may need to
  * grab the data for the blob (or file) for our own in-core comparison.
@@ -1389,6 +1415,9 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
 		char *buf;
 		unsigned long size;
 
+		if (!strcmp(s->path, "-"))
+			return populate_from_stdin(s);
+
 		if (lstat(s->path, &st) < 0) {
 			if (errno == ENOENT) {
 			err_empty:
@@ -1690,6 +1719,10 @@ static void diff_fill_sha1_info(struct diff_filespec *one)
 	if (DIFF_FILE_VALID(one)) {
 		if (!one->sha1_valid) {
 			struct stat st;
+			if (!strcmp(one->path, "-")) {
+				hashcpy(one->sha1, null_sha1);
+				return;
+			}
 			if (lstat(one->path, &st) < 0)
 				die("stat %s", one->path);
 			if (index_path(one->sha1, one->path, &st, 0))