diff: support reading a file from stdin via "-"

This allows you to say

echo Hello World | git diff x -

to compare the contents of file "x" with the line "Hello World".
This automatically switches to --no-index mode.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/diff-lib.c b/diff-lib.c
index 88e59b5794236e8ca3162c8dd823ea1a64b4683b..226f09c72b5d95f90cb5513767b7cd85bb4ac69e 100644 (file)
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -37,14 +37,20 @@ static int queue_diff(struct diff_options *o,
        int mode1 = 0, mode2 = 0;
 
        if (name1) {
-               if (stat(name1, &st))
+               if (!strcmp(name1, "-"))
+                       mode1 = 0644;
+               else if (stat(name1, &st))
                        return error("Could not access '%s'", name1);
-               mode1 = st.st_mode;
+               else
+                       mode1 = st.st_mode;
        }
        if (name2) {
-               if (stat(name2, &st))
+               if (!strcmp(name2, "-"))
+                       mode2 = 0644;
+               else if (stat(name2, &st))
                        return error("Could not access '%s'", name2);
-               mode2 = st.st_mode;
+               else
+                       mode2 = st.st_mode;
        }
 
        if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
@@ -224,7 +230,7 @@ int setup_diff_no_index(struct rev_info *revs,
 {
        int i;
        for (i = 1; i < argc; i++)
-               if (argv[i][0] != '-')
+               if (argv[i][0] != '-' || argv[i][1] == '\0')
                        break;
                else if (!strcmp(argv[i], "--")) {
                        i++;

diff --git a/diff.c b/diff.c
index e225de230599bb35d9fe5b219ff4b8e8de9bfd97..81be6adca3541cd8785e80f6a8f6db61ad11b272 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -1389,6 +1389,22 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
                char *buf;
                unsigned long size;
 
+               if (!strcmp(s->path, "-")) {
+#define INCREMENT 1024
+                       int i = INCREMENT;
+                       size = 0;
+                       buf = NULL;
+                       while (i == INCREMENT) {
+                               buf = xrealloc(buf, size + INCREMENT);
+                               i = xread(0, buf + size, INCREMENT);
+                               size += i;
+                       }
+                       s->should_munmap = 0;
+                       s->data = buf;
+                       s->size = size;
+                       s->should_free = 1;
+                       return 0;
+               }
                if (lstat(s->path, &st) < 0) {
                        if (errno == ENOENT) {
                        err_empty:
@@ -1689,6 +1705,10 @@ 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))