From a5976e638b2548ce96b1987926bd6ac6e357aee1 Mon Sep 17 00:00:00 2001
From: nojaf <florian.verdonck@outlook.com>
Date: Tue, 20 Jun 2023 14:14:24 +0200
Subject: [PATCH] Add typar to member when parent type contains the same
 letter.

---
 src/Compiler/Checking/NicePrint.fs                | 15 ++++++++++++++-
 .../generic-member.fsx                            |  9 +++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 tests/FSharp.Compiler.ComponentTests/Signatures/TestCasesForGenerationRoundTrip/generic-member.fsx

diff --git a/src/Compiler/Checking/NicePrint.fs b/src/Compiler/Checking/NicePrint.fs
index db54e06faf6..50a2ca2b44d 100644
--- a/src/Compiler/Checking/NicePrint.fs
+++ b/src/Compiler/Checking/NicePrint.fs
@@ -1266,8 +1266,21 @@ module PrintTastMemberOrVals =
                 layoutTyconRef denv vref.MemberApparentEntity ^^ SepL.dot ^^ nameL
             else
                 nameL
+
+        let memberHasSameTyparNameAsParentTypeTypars =
+            let parentTyparNames =
+                vref.DeclaringEntity.TyparsNoRange
+                |> Seq.choose (fun tp -> if tp.typar_id.idText = unassignedTyparName then None else Some tp.typar_id.idText)
+                |> set
+            niceMethodTypars
+            |> Seq.exists (fun tp -> parentTyparNames.Contains tp.typar_id.idText)
+
         let typarOrderMismatch = isTyparOrderMismatch niceMethodTypars argInfos
-        let nameL = if denv.showTyparBinding || typarOrderMismatch then layoutTyparDecls denv nameL true niceMethodTypars else nameL
+        let nameL =
+            if denv.showTyparBinding || typarOrderMismatch || memberHasSameTyparNameAsParentTypeTypars then
+                layoutTyparDecls denv nameL true niceMethodTypars
+            else
+                nameL
         let nameL = layoutAccessibility denv vref.Accessibility nameL
         nameL
 
diff --git a/tests/FSharp.Compiler.ComponentTests/Signatures/TestCasesForGenerationRoundTrip/generic-member.fsx b/tests/FSharp.Compiler.ComponentTests/Signatures/TestCasesForGenerationRoundTrip/generic-member.fsx
new file mode 100644
index 00000000000..06a8a25c01a
--- /dev/null
+++ b/tests/FSharp.Compiler.ComponentTests/Signatures/TestCasesForGenerationRoundTrip/generic-member.fsx
@@ -0,0 +1,9 @@
+module V
+
+type 'a Foo =
+    {
+        Bar: 'a array
+        D: int
+    }
+    member _.Make1<'b> (array: 'a array) : 'a Foo = failwith "meh"
+    member _.Make2<'a> (array: 'a array) : 'a Foo = failwith "meh"