From 56840931355fdf8ce12a59ad085d90b04404f831 Mon Sep 17 00:00:00 2001
From: metagn <metagngn@gmail.com>
Date: Tue, 27 Dec 2022 23:24:00 +0300
Subject: [PATCH] fix for bad error message with const in case statement
 (#21182)

* preliminary fix for bad error message with const

* add test case

* fix tmatrixconcept and tmatrixlib
---
 compiler/semfold.nim         | 4 ++++
 tests/errmsgs/tconstinfo.nim | 7 +++++++
 2 files changed, 11 insertions(+)
 create mode 100644 tests/errmsgs/tconstinfo.nim

diff --git a/compiler/semfold.nim b/compiler/semfold.nim
index 7c57eb370..7f966c6fd 100644
--- a/compiler/semfold.nim
+++ b/compiler/semfold.nim
@@ -569,6 +569,8 @@ proc foldDefine(m, s: PSym, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNode
     else: result = copyTree(s.astdef) # unreachable
   else:
     result = copyTree(s.astdef)
+    if result != nil:
+      result.info = n.info
 
 proc getConstExpr(m: PSym, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNode =
   result = nil
@@ -593,6 +595,8 @@ proc getConstExpr(m: PSym, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNode
         result = foldDefine(m, s, n, idgen, g)
       else:
         result = copyTree(s.astdef)
+        if result != nil:
+          result.info = n.info
     of skProc, skFunc, skMethod:
       result = n
     of skParam:
diff --git a/tests/errmsgs/tconstinfo.nim b/tests/errmsgs/tconstinfo.nim
new file mode 100644
index 000000000..170972b9f
--- /dev/null
+++ b/tests/errmsgs/tconstinfo.nim
@@ -0,0 +1,7 @@
+# https://forum.nim-lang.org/t/9762
+
+const foo = "abc"
+case 'a'
+of foo: echo "should error" #[tt.Error
+   ^ type mismatch: got <string> but expected 'char']#
+else: discard