ls-files: prevent prune_cache from overeagerly pruning submodules

Since (ae8d08242 pathspec: pass directory indicator to
match_pathspec_item()) the path matching logic has been able to cope
with submodules without needing to strip off a trailing slash if a path
refers to a submodule.

ls-files is the only caller of 'parse_pathspec()' which relies on the
behavior of the PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP flag because it
uses the result to construct a common prefix of all provided pathspecs
which is then used to prune the index of all entries which don't have
that prefix.  Since submodules entries in the index don't have a
trailing slash 'prune_cache()' will be overeager and prune a submodule
'sub' if the common prefix is 'sub/'.  To correct this behavior, only
prune entries which don't match up to, but not including, a trailing
slash of the common prefix.

This is in preparation to remove the
PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP flag in a later patch.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index a6c70dbe9ec84921108a85485a12111c854833b8..1f3d478443dc00df44dfc8dca571773b74eb7a06 100644 (file)
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -97,7 +97,7 @@ static void show_dir_entry(const char *tag, struct dir_entry *ent)
 {
        int len = max_prefix_len;
 
-       if (len >= ent->len)
+       if (len > ent->len)
                die("git ls-files: internal error - directory entry not superset of prefix");
 
        if (!dir_path_match(ent, &pathspec, len, ps_matched))
@@ -238,7 +238,7 @@ static void show_ce_entry(const char *tag, const struct cache_entry *ce)
                strbuf_addstr(&name, super_prefix);
        strbuf_addstr(&name, ce->name);
 
-       if (len >= ce_namelen(ce))
+       if (len > ce_namelen(ce))
                die("git ls-files: internal error - cache entry not superset of prefix");
 
        if (recurse_submodules && S_ISGITLINK(ce->ce_mode) &&
@@ -403,6 +403,25 @@ static void prune_cache(const char *prefix, size_t prefixlen)
        active_nr = last - pos;
 }
 
+static int get_common_prefix_len(const char *common_prefix)
+{
+       int common_prefix_len;
+
+       if (!common_prefix)
+               return 0;
+
+       common_prefix_len = strlen(common_prefix);
+
+       /*
+        * If the prefix has a trailing slash, strip it so that submodules wont
+        * be pruned from the index.
+        */
+       if (common_prefix[common_prefix_len - 1] == '/')
+               common_prefix_len--;
+
+       return common_prefix_len;
+}
+
 /*
  * Read the tree specified with --with-tree option
  * (typically, HEAD) into stage #1 and then
@@ -624,8 +643,7 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
                    "--error-unmatch");
 
        parse_pathspec(&pathspec, 0,
-                      PATHSPEC_PREFER_CWD |
-                      PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP,
+                      PATHSPEC_PREFER_CWD,
                       prefix, argv);
 
        /*
@@ -637,7 +655,9 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
                max_prefix = NULL;
        else
                max_prefix = common_prefix(&pathspec);
-       max_prefix_len = max_prefix ? strlen(max_prefix) : 0;
+       max_prefix_len = get_common_prefix_len(max_prefix);
+
+       prune_cache(max_prefix, max_prefix_len);
 
        /* Treat unmatching pathspec elements as errors */
        if (pathspec.nr && error_unmatch)
@@ -651,7 +671,6 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
              show_killed || show_modified || show_resolve_undo))
                show_cached = 1;
 
-       prune_cache(max_prefix, max_prefix_len);
        if (with_tree) {
                /*
                 * Basic sanity check; show-stages and show-unmerged