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

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;