From f158c3553e512b2b90b93b5393fff2f31e17c972 Mon Sep 17 00:00:00 2001
From: Dennis <dkorpel@users.noreply.github.com>
Date: Tue, 16 Jul 2024 13:29:57 +0200
Subject: [PATCH] escape.d: Fix handling of isTypesafeVariadicArray (#16709)

---
 compiler/src/dmd/escape.d                  | 23 +++++++---------------
 compiler/test/fail_compilation/fail13902.d |  4 ++--
 compiler/test/fail_compilation/test23022.d |  2 +-
 3 files changed, 10 insertions(+), 19 deletions(-)

diff --git a/compiler/src/dmd/escape.d b/compiler/src/dmd/escape.d
index 847780a80a..473031348b 100644
--- a/compiler/src/dmd/escape.d
+++ b/compiler/src/dmd/escape.d
@@ -1215,7 +1215,13 @@ private bool checkReturnEscapeImpl(ref Scope sc, Expression e, bool refs, bool g
             return;
         }
 
-        if (v.isScope())
+        if (v.isTypesafeVariadicArray && p == sc.func)
+        {
+            if (!gag)
+                sc.eSink.error(e.loc, "returning `%s` escapes a reference to variadic parameter `%s`", e.toChars(), v.toChars());
+            result = false;
+        }
+        else if (v.isScope())
         {
             /* If `return scope` applies to v.
              */
@@ -1270,12 +1276,6 @@ private bool checkReturnEscapeImpl(ref Scope sc, Expression e, bool refs, bool g
                 }
             }
         }
-        else if (v.isTypesafeVariadicArray && p == sc.func)
-        {
-            if (!gag)
-                sc.eSink.error(e.loc, "returning `%s` escapes a reference to variadic parameter `%s`", e.toChars(), v.toChars());
-            result = false;
-        }
         else
         {
             //printf("no infer for %s in %s, %d\n", v.toChars(), sc.func.ident.toChars(), __LINE__);
@@ -2023,15 +2023,6 @@ void escapeByRef(Expression e, ref scope EscapeByResults er, bool retRefTransiti
     void visitIndex(IndexExp e)
     {
         Type tb = e.e1.type.toBasetype();
-        if (auto ve = e.e1.isVarExp())
-        {
-            VarDeclaration v = ve.var.isVarDeclaration();
-            if (v && v.isTypesafeVariadicArray)
-            {
-                er.byRef(v, retRefTransition);
-                return;
-            }
-        }
         if (tb.ty == Tsarray)
         {
             escapeByRef(e.e1, er, retRefTransition);
diff --git a/compiler/test/fail_compilation/fail13902.d b/compiler/test/fail_compilation/fail13902.d
index 47cb65cde2..3d3a4f41cc 100644
--- a/compiler/test/fail_compilation/fail13902.d
+++ b/compiler/test/fail_compilation/fail13902.d
@@ -323,9 +323,9 @@ int[] testSlice2() { int[3] sa; int n; return sa[n..2][1..2]; }
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/fail13902.d(324): Error: returning `vda[0]` escapes a reference to parameter `vda`
+fail_compilation/fail13902.d(324): Error: returning `vda[0]` escapes a reference to variadic parameter `vda`
+fail_compilation/fail13902.d(325): Error: returning `vda[]` escapes a reference to variadic parameter `vda`
 ---
-
 */
 ref int testDynamicArrayVariadic1(int[] vda...) { return vda[0]; }
 @safe int[]   testDynamicArrayVariadic2(int[] vda...) { return vda[]; }
diff --git a/compiler/test/fail_compilation/test23022.d b/compiler/test/fail_compilation/test23022.d
index 8c4eca9c56..db1f4a712c 100644
--- a/compiler/test/fail_compilation/test23022.d
+++ b/compiler/test/fail_compilation/test23022.d
@@ -2,7 +2,7 @@
 REQUIRED_ARGS: -preview=dip1000
 TEST_OUTPUT:
 ---
-fail_compilation/test23022.d(14): Error: scope parameter `p` may not be returned
+fail_compilation/test23022.d(14): Error: returning `p` escapes a reference to variadic parameter `p`
 ---
 */