diff-index.c: "git diff" has no need to read blob from the standard input

Only "diff --no-index -" does.  Bolting the logic into the low-level
function diff_populate_filespec() was a layering violation from day
one.  Move populate_from_stdin() function out of the generic diff.c
to its only user, diff-index.c.

Also make sure "-" from the command line stays a special token "read
from the standard input", even if we later decide to sanitize the
result from prefix_filename() function in a few obvious ways,
e.g. removing unnecessary "./" prefix, duplicated slashes "//" in
the middle, etc.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/diff-no-index.c b/diff-no-index.c
index ac41b68b0a121b8068cae78ddd328387fb11ce0f..09656bca1d192f21f36ff56f2446c6bcc73442f4 100644 (file)
--- a/diff-no-index.c
+++ b/diff-no-index.c
@@ -32,6 +32,13 @@ static int read_directory(const char *path, struct string_list *list)
        return 0;
 }
 
+/*
+ * This should be "(standard input)" or something, but it will
+ * probably expose many more breakages in the way no-index code
+ * is bolted onto the diff callchain.
+ */
+static const char file_from_standard_input[] = "-";
+
 static int get_mode(const char *path, int *mode)
 {
        struct stat st;
@@ -42,7 +49,7 @@ static int get_mode(const char *path, int *mode)
        else if (!strcasecmp(path, "nul"))
                *mode = 0;
 #endif
-       else if (!strcmp(path, "-"))
+       else if (path == file_from_standard_input)
                *mode = create_ce_mode(0666);
        else if (lstat(path, &st))
                return error("Could not access '%s'", path);
@@ -51,6 +58,36 @@ static int get_mode(const char *path, int *mode)
        return 0;
 }
 
+static int populate_from_stdin(struct diff_filespec *s)
+{
+       struct strbuf buf = STRBUF_INIT;
+       size_t size = 0;
+
+       if (strbuf_read(&buf, 0, 0) < 0)
+               return error("error while reading from stdin %s",
+                                    strerror(errno));
+
+       s->should_munmap = 0;
+       s->data = strbuf_detach(&buf, &size);
+       s->size = size;
+       s->should_free = 1;
+       s->is_stdin = 1;
+       return 0;
+}
+
+static struct diff_filespec *noindex_filespec(const char *name, int mode)
+{
+       struct diff_filespec *s;
+
+       if (!name)
+               name = "/dev/null";
+       s = alloc_filespec(name);
+       fill_filespec(s, null_sha1, mode);
+       if (name == file_from_standard_input)
+               populate_from_stdin(s);
+       return s;
+}
+
 static int queue_diff(struct diff_options *o,
                const char *name1, const char *name2)
 {
@@ -135,15 +172,8 @@ static int queue_diff(struct diff_options *o,
                        tmp_c = name1; name1 = name2; name2 = tmp_c;
                }
 
-               if (!name1)
-                       name1 = "/dev/null";
-               if (!name2)
-                       name2 = "/dev/null";
-               d1 = alloc_filespec(name1);
-               d2 = alloc_filespec(name2);
-               fill_filespec(d1, null_sha1, mode1);
-               fill_filespec(d2, null_sha1, mode2);
-
+               d1 = noindex_filespec(name1, mode1);
+               d2 = noindex_filespec(name2, mode2);
                diff_queue(&diff_queued_diff, d1, d2);
                return 0;
        }
@@ -238,7 +268,7 @@ void diff_no_index(struct rev_info *revs,
                         * stdin should be spelled as "-"; if you have
                         * path that is "-", spell it as "./-".
                         */
-                       p = p;
+                       p = file_from_standard_input;
                else if (prefixlen)
                        p = xstrdup(prefix_filename(prefix, prefixlen, p));
                paths[i] = p;

diff --git a/diff.c b/diff.c
index 9038f190ece061696a3290acf8f1e9951e9d0a6c..d6fdb8e31fd24d3a6479d1c5e1f5c7fe19b03c81 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -2426,22 +2426,6 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
        return 0;
 }
 
-static int populate_from_stdin(struct diff_filespec *s)
-{
-       struct strbuf buf = STRBUF_INIT;
-       size_t size = 0;
-
-       if (strbuf_read(&buf, 0, 0) < 0)
-               return error("error while reading from stdin %s",
-                                    strerror(errno));
-
-       s->should_munmap = 0;
-       s->data = strbuf_detach(&buf, &size);
-       s->size = size;
-       s->should_free = 1;
-       return 0;
-}
-
 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
 {
        int len;
@@ -2491,9 +2475,6 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
                struct stat st;
                int fd;
 
-               if (!strcmp(s->path, "-"))
-                       return populate_from_stdin(s);
-
                if (lstat(s->path, &st) < 0) {
                        if (errno == ENOENT) {
                        err_empty:
@@ -2855,7 +2836,7 @@ 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, "-")) {
+                       if (one->is_stdin) {
                                hashcpy(one->sha1, null_sha1);
                                return;
                        }

diff --git a/diffcore.h b/diffcore.h
index b8f1fdecf4d9e5e8f8e834eb55a374f1af8352fd..ae43149620ee269ddddfcec06d618dcc76c52895 100644 (file)
--- a/diffcore.h
+++ b/diffcore.h
@@ -43,6 +43,7 @@ struct diff_filespec {
        unsigned should_free : 1; /* data should be free()'ed */
        unsigned should_munmap : 1; /* data should be munmap()'ed */
        unsigned dirty_submodule : 2;  /* For submodules: its work tree is dirty */
+       unsigned is_stdin : 1;
 #define DIRTY_SUBMODULE_UNTRACKED 1
 #define DIRTY_SUBMODULE_MODIFIED  2
 

diff --git a/t/t7501-commit.sh b/t/t7501-commit.sh
index 3ad04363b5920497617f806a18a3a5a0083ac1b9..e6cf6ee9e76ec4f2f56dd2c66460756dcc02558d 100755 (executable)
--- a/t/t7501-commit.sh
+++ b/t/t7501-commit.sh
@@ -458,4 +458,16 @@ test_expect_success 'amend can copy notes' '
 
 '
 
+test_expect_success 'commit a file whose name is a dash' '
+       git reset --hard &&
+       for i in 1 2 3 4 5
+       do
+               echo $i
+       done >./- &&
+       git add ./- &&
+       test_tick &&
+       git commit -m "add dash" >output </dev/null &&
+       test_i18ngrep " changed, 5 insertions" output
+'
+
 test_done