eval: Fix -delete when following symlinks.

Same bug as https://savannah.gnu.org/bugs/?46305.  Please don't ever do
this though.

3 files changed, 31 insertions, 2 deletions

diff --git a/eval.c b/eval.c
index a4ee5c5..9308a17 100644
--- a/eval.c
+++ b/eval.c
@@ -277,8 +277,21 @@ bool eval_delete(const struct expr *expr, struct eval_state *state) {
 	}
 
 	int flag = 0;
-	if (ftwbuf->typeflag == BFTW_DIR) {
-		flag |= AT_REMOVEDIR;
+	if (ftwbuf->at_flags & AT_SYMLINK_NOFOLLOW) {
+		if (ftwbuf->typeflag == BFTW_DIR) {
+			flag |= AT_REMOVEDIR;
+		}
+	} else {
+		// We need to know the actual type of the path, not what it points to
+		struct bfs_stat sb;
+		if (bfs_stat(ftwbuf->at_fd, ftwbuf->at_path, ftwbuf->at_flags | AT_SYMLINK_NOFOLLOW, 0, &sb) == 0) {
+			if (S_ISDIR(sb.mode)) {
+				flag |= AT_REMOVEDIR;
+			}
+		} else {
+			eval_error(state);
+			return false;
+		}
 	}
 
 	if (unlinkat(ftwbuf->at_fd, ftwbuf->at_path, flag) != 0) {
diff --git a/tests.sh b/tests.sh
index b74e067..3e47374 100755
--- a/tests.sh
+++ b/tests.sh
@@ -266,6 +266,7 @@ bsd_tests=(
     test_ok_stdin
     test_okdir_stdin
     test_delete
+    test_L_delete
     test_rm
     test_regex
     test_iregex
@@ -369,6 +370,7 @@ gnu_tests=(
     test_perm_symbolic_slash
     test_perm_leading_plus_symbolic_slash
     test_delete
+    test_L_delete
     test_regex
     test_iregex
     test_regex_parens
@@ -1177,6 +1179,18 @@ function test_delete() {
     bfs_diff scratch
 }
 
+function test_L_delete() {
+    rm -rf scratch/*
+    mkdir scratch/foo
+    mkdir scratch/bar
+    ln -s ../foo scratch/bar/baz
+
+    # Don't try to rmdir() a symlink
+    invoke_bfs -L scratch/bar -delete || return 1
+
+    bfs_diff scratch
+}
+
 function test_rm() {
     rm -rf scratch/*
     touchp scratch/foo/bar/baz
diff --git a/tests/test_L_delete.out b/tests/test_L_delete.out
new file mode 100644
index 0000000..ed0e9a1
--- /dev/null
+++ b/tests/test_L_delete.out
@@ -0,0 +1,2 @@
+scratch
+scratch/foo