From 986ed33debd2de711edda36320d34ec343f36375 Mon Sep 17 00:00:00 2001
From: Felipe Pena <felipensp@gmail.com>
Date: Mon, 28 Oct 2024 09:05:38 -0300
Subject: [PATCH] cgen: fix dump of alias to option fn type (fix #22670)
 (#22676)

---
 vlib/v/gen/c/dumpexpr.v                     | 14 ++++++++++----
 vlib/v/tests/options/option_fn_alias_test.v | 12 ++++++++++++
 2 files changed, 22 insertions(+), 4 deletions(-)
 create mode 100644 vlib/v/tests/options/option_fn_alias_test.v

diff --git a/vlib/v/gen/c/dumpexpr.v b/vlib/v/gen/c/dumpexpr.v
index 6bc85f18c..ce6506cbd 100644
--- a/vlib/v/gen/c/dumpexpr.v
+++ b/vlib/v/gen/c/dumpexpr.v
@@ -106,20 +106,26 @@ fn (mut g Gen) dump_expr_definitions() {
 		is_ptr := typ.is_ptr()
 		deref, _ := deref_kind(str_method_expects_ptr, is_ptr, typ)
 		to_string_fn_name := g.get_str_fn(typ.clear_flags(.shared_f, .result))
+		is_option := typ.has_option_or_result()
 		mut ptr_asterisk := if is_ptr { '*'.repeat(typ.nr_muls()) } else { '' }
 		mut str_dumparg_type := ''
 		mut str_dumparg_ret_type := ''
 		if dump_sym.kind == .none {
 			str_dumparg_type = 'IError' + ptr_asterisk
+		} else if dump_sym.kind == .function {
+			if is_option {
+				ptr_asterisk = ptr_asterisk.replace('*', '_ptr')
+			}
+			str_dumparg_type += g.styp(typ).replace('*', '') + ptr_asterisk
 		} else {
-			if typ.has_flag(.option) {
+			if is_option {
 				str_dumparg_type += '_option_'
 				ptr_asterisk = ptr_asterisk.replace('*', '_ptr')
 			}
 			str_dumparg_type += g.cc_type(typ, true) + ptr_asterisk
 		}
 		mut is_fixed_arr_ret := false
-		if dump_sym.kind == .function {
+		if dump_sym.kind == .function && !is_option {
 			fninfo := dump_sym.info as ast.FnType
 			str_dumparg_type = 'DumpFNType_${name}'
 			tdef_pos := g.out.len
@@ -128,7 +134,7 @@ fn (mut g Gen) dump_expr_definitions() {
 			g.go_back(str_tdef.len)
 			dump_typedefs['typedef ${str_tdef};'] = true
 			str_dumparg_ret_type = str_dumparg_type
-		} else if !typ.has_option_or_result() && dump_sym.is_array_fixed() {
+		} else if !is_option && dump_sym.is_array_fixed() {
 			match dump_sym.kind {
 				.array_fixed {
 					if (dump_sym.info as ast.ArrayFixed).is_fn_ret {
@@ -172,7 +178,7 @@ fn (mut g Gen) dump_expr_definitions() {
 		}
 		mut surrounder := util.new_surrounder(3)
 		surrounder.add('\tstring sline = int_str(line);', '\tstring_free(&sline);')
-		if dump_sym.kind == .function {
+		if dump_sym.kind == .function && !is_option {
 			surrounder.add('\tstring value = ${to_string_fn_name}();', '\tstring_free(&value);')
 		} else if dump_sym.kind == .none {
 			surrounder.add('\tstring value = _SLIT("none");', '\tstring_free(&value);')
diff --git a/vlib/v/tests/options/option_fn_alias_test.v b/vlib/v/tests/options/option_fn_alias_test.v
new file mode 100644
index 000000000..ac2c8e940
--- /dev/null
+++ b/vlib/v/tests/options/option_fn_alias_test.v
@@ -0,0 +1,12 @@
+type Foo = fn (bar string)
+
+fn test_main() {
+	mut func := ?Foo(none)
+	res := dump(func)
+	assert res == none
+
+	mut func2 := ?Foo(fn (bar string) {})
+	res2 := dump(func2)
+	assert res2 != none
+	assert res2?.str() == 'fn (string)'
+}
-- 
2.39.5