git-filter-branch: more detailed USAGE

diff --git a/builtin-ls-files.c b/builtin-ls-files.c
index 61577ea13ffdf0143dcb8a13c37ae49c1f8f2018..cce17b5ced173ff7ecc1348eb3163609b15982ca 100644 (file)
--- a/builtin-ls-files.c
+++ b/builtin-ls-files.c
@@ -469,9 +469,11 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
                break;
        }
 
-       if (require_work_tree &&
-                       (!is_inside_work_tree() || is_inside_git_dir()))
-               die("This operation must be run in a work tree");
+       if (require_work_tree && !is_inside_work_tree()) {
+               const char *work_tree = get_git_work_tree();
+               if (!work_tree || chdir(work_tree))
+                       die("This operation must be run in a work tree");
+       }
 
        pathspec = get_pathspec(prefix, argv + i);
 
@@ -509,8 +511,28 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
                 */
                int num, errors = 0;
                for (num = 0; pathspec[num]; num++) {
+                       int other, found_dup;
+
                        if (ps_matched[num])
                                continue;
+                       /*
+                        * The caller might have fed identical pathspec
+                        * twice.  Do not barf on such a mistake.
+                        */
+                       for (found_dup = other = 0;
+                            !found_dup && pathspec[other];
+                            other++) {
+                               if (other == num || !ps_matched[other])
+                                       continue;
+                               if (!strcmp(pathspec[other], pathspec[num]))
+                                       /*
+                                        * Ok, we have a match already.
+                                        */
+                                       found_dup = 1;
+                       }
+                       if (found_dup)
+                               continue;
+
                        error("pathspec '%s' did not match any file(s) known to git.",
                              pathspec[num] + prefix_offset);
                        errors++;