builtin-add.c: restructure the code for maintainability

The implementation of "git add" has four major codepaths that are mutually
exclusive:

 - if "--interactive" or "--patch" is given, spawn "git add--interactive"
   and exit without doing anything else.  Otherwise things are handled
   internally in this C code;

 - if "--update" is given, update the modified files and exit without
   doing anything else;

 - if "--refresh" is given, do refresh and exit without doing anything
   else;

 - otherwise, find the paths that match pathspecs and stage their
   contents.

It led to an unholy mess in the code structure; each of the latter three
codepaths has a separate call to read_cache(), even though they are all
about "read the current index, update it and write it back", and logically
they should read the index once _anyway_.

This cleans up the latter three cases by introducing a pair of helper
variables:

 - "add_new_files" is set if we need to scan the working tree for paths
   that match the pathspec.  This variable is false for "--update" and
   "--refresh", because they only work on already tracked files.

 - "require_pathspec" is set if the user must give at least one pathspec.
   "--update" does not need it but all the other cases do.

This is in preparation for introducing a new option "--all", that does the
equivalent of "git add -u && git add ." (aka "addremove").

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

diff --git a/builtin-add.c b/builtin-add.c
index bf13aa3ad6e55075af4f727f73b8c41861b8693e..9b2ee8c136f6e653d0b076894d9438e2ac4315ef 100644 (file)
--- a/builtin-add.c
+++ b/builtin-add.c
@@ -140,8 +140,6 @@ static void refresh(int verbose, const char **pathspec)
        for (specs = 0; pathspec[specs];  specs++)
                /* nothing */;
        seen = xcalloc(specs, 1);
-       if (read_cache() < 0)
-               die("index file corrupt");
        refresh_index(&the_index, verbose ? 0 : REFRESH_QUIET, pathspec, seen);
        for (i = 0; i < specs; i++) {
                if (!seen[i])
@@ -216,13 +214,36 @@ static int add_config(const char *var, const char *value, void *cb)
        return git_default_config(var, value, cb);
 }
 
+static int add_files(struct dir_struct *dir, int flags)
+{
+       int i, exit_status = 0;
+
+       if (dir->ignored_nr) {
+               fprintf(stderr, ignore_error);
+               for (i = 0; i < dir->ignored_nr; i++)
+                       fprintf(stderr, "%s\n", dir->ignored[i]->name);
+               fprintf(stderr, "Use -f if you really want to add them.\n");
+               die("no files added");
+       }
+
+       for (i = 0; i < dir->nr; i++)
+               if (add_file_to_cache(dir->entries[i]->name, flags)) {
+                       if (!ignore_add_errors)
+                               die("adding files failed");
+                       exit_status = 1;
+               }
+       return exit_status;
+}
+
 int cmd_add(int argc, const char **argv, const char *prefix)
 {
        int exit_status = 0;
-       int i, newfd;
+       int newfd;
        const char **pathspec;
        struct dir_struct dir;
        int flags;
+       int add_new_files;
+       int require_pathspec;
 
        argc = parse_options(argc, argv, builtin_add_options,
                          builtin_add_usage, 0);
@@ -233,53 +254,43 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 
        git_config(add_config, NULL);
 
+       add_new_files = !take_worktree_changes && !refresh_only;
+       require_pathspec = !take_worktree_changes;
+
        newfd = hold_locked_index(&lock_file, 1);
 
        flags = ((verbose ? ADD_CACHE_VERBOSE : 0) |
                 (show_only ? ADD_CACHE_PRETEND : 0) |
                 (ignore_add_errors ? ADD_CACHE_IGNORE_ERRORS : 0));
 
-       if (take_worktree_changes) {
-               const char **pathspec;
-               if (read_cache() < 0)
-                       die("index file corrupt");
-               pathspec = get_pathspec(prefix, argv);
-               exit_status = add_files_to_cache(prefix, pathspec, flags);
-               goto finish;
-       }
-
-       if (argc == 0) {
+       if (require_pathspec && argc == 0) {
                fprintf(stderr, "Nothing specified, nothing added.\n");
                fprintf(stderr, "Maybe you wanted to say 'git add .'?\n");
                return 0;
        }
        pathspec = get_pathspec(prefix, argv);
 
-       if (refresh_only) {
-               refresh(verbose, pathspec);
-               goto finish;
-       }
-
-       fill_directory(&dir, pathspec, ignored_too);
+       /*
+        * If we are adding new files, we need to scan the working
+        * tree to find the ones that match pathspecs; this needs
+        * to be done before we read the index.
+        */
+       if (add_new_files)
+               fill_directory(&dir, pathspec, ignored_too);
 
        if (read_cache() < 0)
                die("index file corrupt");
 
-       if (dir.ignored_nr) {
-               fprintf(stderr, ignore_error);
-               for (i = 0; i < dir.ignored_nr; i++) {
-                       fprintf(stderr, "%s\n", dir.ignored[i]->name);
-               }
-               fprintf(stderr, "Use -f if you really want to add them.\n");
-               die("no files added");
+       if (refresh_only) {
+               refresh(verbose, pathspec);
+               goto finish;
        }
 
-       for (i = 0; i < dir.nr; i++)
-               if (add_file_to_cache(dir.entries[i]->name, flags)) {
-                       if (!ignore_add_errors)
-                               die("adding files failed");
-                       exit_status = 1;
-               }
+       if (take_worktree_changes)
+               exit_status |= add_files_to_cache(prefix, pathspec, flags);
+
+       if (add_new_files)
+               exit_status |= add_files(&dir, flags);
 
  finish:
        if (active_cache_changed) {