Teach run-command about stdout redirection

diff --git a/diff-lib.c b/diff-lib.c
index 88e59b5794236e8ca3162c8dd823ea1a64b4683b..6abb981534bf032d50e28eb3a14033c1b6546762 100644 (file)
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -30,22 +30,28 @@ static int read_directory(const char *path, struct path_list *list)
        return 0;
 }
 
+static int get_mode(const char *path, int *mode)
+{
+       struct stat st;
+
+       if (!path || !strcmp(path, "/dev/null"))
+               *mode = 0;
+       else if (!strcmp(path, "-"))
+               *mode = ntohl(create_ce_mode(0666));
+       else if (stat(path, &st))
+               return error("Could not access '%s'", path);
+       else
+               *mode = st.st_mode;
+       return 0;
+}
+
 static int queue_diff(struct diff_options *o,
                const char *name1, const char *name2)
 {
-       struct stat st;
        int mode1 = 0, mode2 = 0;
 
-       if (name1) {
-               if (stat(name1, &st))
-                       return error("Could not access '%s'", name1);
-               mode1 = st.st_mode;
-       }
-       if (name2) {
-               if (stat(name2, &st))
-                       return error("Could not access '%s'", name2);
-               mode2 = st.st_mode;
-       }
+       if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
+               return -1;
 
        if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
                return error("file/directory conflict: %s, %s", name1, name2);
@@ -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++;
@@ -254,9 +260,15 @@ int setup_diff_no_index(struct rev_info *revs,
 
                revs->diffopt.paths = xcalloc(2, sizeof(char*));
                for (i = 0; i < 2; i++) {
-                       const char *p;
-                       p = prefix_filename(prefix, len, argv[argc - 2 + i]);
-                       revs->diffopt.paths[i] = xstrdup(p);
+                       const char *p = argv[argc - 2 + i];
+                       /*
+                        * stdin should be spelled as '-'; if you have
+                        * path that is '-', spell it as ./-.
+                        */
+                       p = (strcmp(p, "-")
+                            ? xstrdup(prefix_filename(prefix, len, p))
+                            : p);
+                       revs->diffopt.paths[i] = p;
                }
        }
        else
@@ -412,6 +424,9 @@ int run_diff_files(struct rev_info *revs, int silent_on_removed)
                    S_ISREG(newmode) && S_ISREG(oldmode) &&
                    ((newmode ^ oldmode) == 0111))
                        newmode = oldmode;
+               else if (!has_symlinks &&
+                   S_ISREG(newmode) && S_ISLNK(oldmode))
+                       newmode = oldmode;
                diff_change(&revs->diffopt, oldmode, newmode,
                            ce->sha1, (changed ? null_sha1 : ce->sha1),
                            ce->name, NULL);