update-index: stat updated files earlier

In the update_one(), we check verify_path() on the proposed
path before doing anything else. In preparation for having
verify_path() look at the file mode, let's stat the file
earlier, so we can check the mode accurately.

This is made a bit trickier by the fact that this function
only does an lstat in a few code paths (the ones that flow
down through process_path()). So we can speculatively do the
lstat() here and pass the results down, and just use a dummy
mode for cases where we won't actually be updating the index
from the filesystem.

Signed-off-by: Jeff King <peff@peff.net>

diff --git a/builtin/update-index.c b/builtin/update-index.c
index ebfc09faa0d604218af8f5815af5e5fee5915158..8d152ded779ad48426d6956f30a4ef6c7ea9238c 100644 (file)
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -358,10 +358,9 @@ static int process_directory(const char *path, int len, struct stat *st)
        return error("%s: is a directory - add files inside instead", path);
 }
 
-static int process_path(const char *path)
+static int process_path(const char *path, struct stat *st, int stat_errno)
 {
        int pos, len;
-       struct stat st;
        const struct cache_entry *ce;
 
        len = strlen(path);
@@ -385,13 +384,13 @@ static int process_path(const char *path)
         * First things first: get the stat information, to decide
         * what to do about the pathname!
         */
-       if (lstat(path, &st) < 0)
-               return process_lstat_error(path, errno);
+       if (stat_errno)
+               return process_lstat_error(path, stat_errno);
 
-       if (S_ISDIR(st.st_mode))
-               return process_directory(path, len, &st);
+       if (S_ISDIR(st->st_mode))
+               return process_directory(path, len, st);
 
-       return add_one_path(ce, path, len, &st);
+       return add_one_path(ce, path, len, st);
 }
 
 static int add_cacheinfo(unsigned int mode, const struct object_id *oid,
@@ -443,6 +442,16 @@ static void chmod_path(char flip, const char *path)
 
 static void update_one(const char *path)
 {
+       int stat_errno = 0;
+       struct stat st;
+
+       if (mark_valid_only || mark_skip_worktree_only || force_remove)
+               st.st_mode = 0;
+       else if (lstat(path, &st) < 0) {
+               st.st_mode = 0;
+               stat_errno = errno;
+       } /* else stat is valid */
+
        if (!verify_path(path)) {
                fprintf(stderr, "Ignoring path %s\n", path);
                return;
@@ -464,7 +473,7 @@ static void update_one(const char *path)
                report("remove '%s'", path);
                return;
        }
-       if (process_path(path))
+       if (process_path(path, &st, stat_errno))
                die("Unable to process path %s", path);
        report("add '%s'", path);
 }