From 1e88b1ab3ecea6d9195fbbbbd702de68837b7e7c Mon Sep 17 00:00:00 2001
From: Felipe Pena <felipensp@gmail.com>
Date: Thu, 18 May 2023 06:25:19 -0300
Subject: [PATCH] cgen: fix missing panic message for 'option not set' on debug
 (#18168)

---
 vlib/v/gen/c/cgen.v                      | 2 +-
 vlib/v/slow_tests/inout/option_panic.out | 5 +++++
 vlib/v/slow_tests/inout/option_panic.vv  | 8 ++++++++
 3 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 vlib/v/slow_tests/inout/option_panic.out
 create mode 100644 vlib/v/slow_tests/inout/option_panic.vv

diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index 85434893ee..fd958d8007 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -5958,7 +5958,7 @@ fn (mut g Gen) or_block(var_name string, or_block ast.OrExpr, return_type ast.Ty
 			err_msg := 'IError_name_table[${cvar_name}.err._typ]._method_msg(${cvar_name}.err._object)'
 			if g.pref.is_debug {
 				paline, pafile, pamod, pafn := g.panic_debug_info(or_block.pos)
-				g.writeln('panic_debug(${paline}, tos3("${pafile}"), tos3("${pamod}"), tos3("${pafn}"), ${err_msg} );')
+				g.writeln('panic_debug(${paline}, tos3("${pafile}"), tos3("${pamod}"), tos3("${pafn}"), ${err_msg}.len == 0 ? _SLIT("option not set ()") : ${err_msg});')
 			} else {
 				g.writeln('\tpanic_option_not_set( ${err_msg} );')
 			}
diff --git a/vlib/v/slow_tests/inout/option_panic.out b/vlib/v/slow_tests/inout/option_panic.out
new file mode 100644
index 0000000000..d80b7e2f97
--- /dev/null
+++ b/vlib/v/slow_tests/inout/option_panic.out
@@ -0,0 +1,5 @@
+================ V panic ================
+   module: main
+ function: main()
+  message: option not set ()
+     file: vlib/v/slow_tests/inout/option_panic.vv:7
\ No newline at end of file
diff --git a/vlib/v/slow_tests/inout/option_panic.vv b/vlib/v/slow_tests/inout/option_panic.vv
new file mode 100644
index 0000000000..30768d355c
--- /dev/null
+++ b/vlib/v/slow_tests/inout/option_panic.vv
@@ -0,0 +1,8 @@
+fn t() ? {
+	a := ?string(none)
+	println(a?)
+}
+
+fn main() {
+	t()?
+}