notmuch new: Fix regression preventing recursion through symlinks.

In commit 3df737bc4addfce71c647792ee668725e5221a98 we switched from
using stat() to using the d_type field in the result of scandir() to
determine whether a filename is a regular file or a directory. This
change introduced a regression in that the recursion would no longer
traverse through a symlink to a directory. (Since stat() would resolve
the symlink but with scandir() we see a distinct DT_LNK value in
d_type).

We fix this for directories by allowing both DT_DIR and DT_LNK values
to recurse, and then downgrading the existing not-a-directory check
within the recursion to not be an error. We also add a new
not-a-directory check outside the recursion that is an error.

1 files changed, 18 insertions, 5 deletions

diff --git a/notmuch-new.c b/notmuch-new.c
index c15f6837..e2b5878f 100644
--- a/notmuch-new.c
+++ b/notmuch-new.c
@@ -229,10 +229,11 @@ add_files_recursive (notmuch_database_t *notmuch,
 	return NOTMUCH_STATUS_FILE_ERROR;
     }
 
-    if (! S_ISDIR (st.st_mode)) {
-	fprintf (stderr, "Error: %s is not a directory.\n", path);
-	return NOTMUCH_STATUS_FILE_ERROR;
-    }
+    /* This is not an error since we may have recursed based on a
+     * symlink to a regular file, not a directory, and we don't know
+     * that until this stat. */
+    if (! S_ISDIR (st.st_mode))
+	return NOTMUCH_STATUS_SUCCESS;
 
     fs_mtime = st.st_mtime;
 
@@ -262,7 +263,7 @@ add_files_recursive (notmuch_database_t *notmuch,
 
 	entry = fs_entries[i];
 
-	if (entry->d_type != DT_DIR)
+	if (entry->d_type != DT_DIR && entry->d_type != DT_LNK)
 	    continue;
 
 	/* Ignore special directories to avoid infinite recursion.
@@ -447,6 +448,7 @@ add_files (notmuch_database_t *notmuch,
     struct sigaction action;
     struct itimerval timerval;
     notmuch_bool_t timer_is_active = FALSE;
+    struct stat st;
 
     if (state->output_is_a_tty && ! debugger_is_active () && ! state->verbose) {
 	/* Setup our handler for SIGALRM */
@@ -466,6 +468,17 @@ add_files (notmuch_database_t *notmuch,
 	timer_is_active = TRUE;
     }
 
+    if (stat (path, &st)) {
+	fprintf (stderr, "Error reading directory %s: %s\n",
+		 path, strerror (errno));
+	return NOTMUCH_STATUS_FILE_ERROR;
+    }
+
+    if (! S_ISDIR (st.st_mode)) {
+	fprintf (stderr, "Error: %s is not a directory.\n", path);
+	return NOTMUCH_STATUS_FILE_ERROR;
+    }
+
     status = add_files_recursive (notmuch, path, state);
 
     if (timer_is_active) {