opt: Fix an invalid assertion in sink_not_comma()

When optimizing -not \( -a , -b \), the child is a comma expression, not
the parent.

Fixes: 4a36bb9 ("expr: Make expressions variadic")

3 files changed, 39 insertions, 4 deletions

diff --git a/src/opt.c b/src/opt.c
index 86ce694..6b51d85 100644
--- a/src/opt.c
+++ b/src/opt.c
@@ -1402,12 +1402,11 @@ static struct bfs_expr *sink_not_andor(struct bfs_opt *opt, struct bfs_expr *exp
 
 /** Sink a negation into a comma expression. */
 static struct bfs_expr *sink_not_comma(struct bfs_opt *opt, struct bfs_expr *expr) {
-	bfs_assert(expr->eval_fn == eval_comma);
-
-	opt_enter(opt, "%pe\n", expr);
-
 	char **argv = expr->argv;
 	expr = only_child(expr);
+	opt_enter(opt, "%pe\n", expr);
+
+	bfs_assert(expr->eval_fn == eval_comma);
 
 	struct bfs_exprs children;
 	foster_children(expr, &children);
diff --git a/tests/gnu/not_comma.out b/tests/gnu/not_comma.out
new file mode 100644
index 0000000..b90468e
--- /dev/null
+++ b/tests/gnu/not_comma.out
@@ -0,0 +1,34 @@
+basic
+basic
+basic/a
+basic/a
+basic/b
+basic/b
+basic/c
+basic/c
+basic/c/d
+basic/c/d
+basic/e
+basic/e
+basic/e/f
+basic/g
+basic/g
+basic/g/h
+basic/g/h
+basic/i
+basic/i
+basic/j
+basic/j
+basic/j/foo
+basic/k
+basic/k
+basic/k/foo
+basic/k/foo/bar
+basic/k/foo/bar
+basic/l
+basic/l
+basic/l/foo
+basic/l/foo/bar
+basic/l/foo/bar
+basic/l/foo/bar/baz
+basic/l/foo/bar/baz
diff --git a/tests/gnu/not_comma.sh b/tests/gnu/not_comma.sh
new file mode 100644
index 0000000..04c0195
--- /dev/null
+++ b/tests/gnu/not_comma.sh
@@ -0,0 +1,2 @@
+# Regression test: assertion failure in sink_not_comma()
+bfs_diff basic -not \( -print , -name '*f*' \) -print