core.excludesfile clean-up

There are inconsistencies in the way commands currently handle
the core.excludesfile configuration variable.  The problem is
the variable is too new to be noticed by anything other than
git-add and git-status.

 * git-ls-files does not notice any of the "ignore" files by
   default, as it predates the standardized set of ignore files.
   The calling scripts established the convention to use
   .git/info/exclude, .gitignore, and later core.excludesfile.

 * git-add and git-status know about it because they call
   add_excludes_from_file() directly with their own notion of
   which standard set of ignore files to use.  This is just a
   stupid duplication of code that need to be updated every time
   the definition of the standard set of ignore files is
   changed.

 * git-read-tree takes --exclude-per-directory=<gitignore>,
   not because the flexibility was needed.  Again, this was
   because the option predates the standardization of the ignore
   files.

 * git-merge-recursive uses hardcoded per-directory .gitignore
   and nothing else.  git-clean (scripted version) does not
   honor core.* because its call to underlying ls-files does not
   know about it.  git-clean in C (parked in 'pu') doesn't either.

We probably could change git-ls-files to use the standard set
when no excludes are specified on the command line and ignore
processing was asked, or something like that, but that will be a
change in semantics and might break people's scripts in a subtle
way.  I am somewhat reluctant to make such a change.

On the other hand, I think it makes perfect sense to fix
git-read-tree, git-merge-recursive and git-clean to follow the
same rule as other commands.  I do not think of a valid use case
to give an exclude-per-directory that is nonstandard to
read-tree command, outside a "negative" test in the t1004 test
script.

This patch is the first step to untangle this mess.

The next step would be to teach read-tree, merge-recursive and
clean (in C) to use setup_standard_excludes().

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

1 files changed, 2 insertions, 20 deletions

diff --git a/builtin-add.c b/builtin-add.c
index 77dcde693..cf815a0b8 100644
--- a/builtin-add.c
+++ b/builtin-add.c
@@ -21,7 +21,6 @@ static const char * const builtin_add_usage[] = {
 };
 
 static int take_worktree_changes;
-static const char *excludes_file;
 
 static void prune_directory(struct dir_struct *dir, const char **pathspec, int prefix)
 {
@@ -61,12 +60,7 @@ static void fill_directory(struct dir_struct *dir, const char **pathspec,
 	memset(dir, 0, sizeof(*dir));
 	if (!ignored_too) {
 		dir->collect_ignored = 1;
-		dir->exclude_per_dir = ".gitignore";
-		path = git_path("info/exclude");
-		if (!access(path, R_OK))
-			add_excludes_from_file(dir, path);
-		if (excludes_file != NULL && !access(excludes_file, R_OK))
-			add_excludes_from_file(dir, excludes_file);
+		setup_standard_excludes(dir);
 	}
 
 	/*
@@ -141,18 +135,6 @@ static void refresh(int verbose, const char **pathspec)
         free(seen);
 }
 
-static int git_add_config(const char *var, const char *value)
-{
-	if (!strcmp(var, "core.excludesfile")) {
-		if (!value)
-			die("core.excludesfile without value");
-		excludes_file = xstrdup(value);
-		return 0;
-	}
-
-	return git_default_config(var, value);
-}
-
 int interactive_add(void)
 {
 	const char *argv[2] = { "add--interactive", NULL };
@@ -193,7 +175,7 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 		exit(interactive_add());
 	}
 
-	git_config(git_add_config);
+	git_config(git_default_config);
 
 	newfd = hold_locked_index(&lock_file, 1);