From 8496690ed0f812c72b008f609106c933871be484 Mon Sep 17 00:00:00 2001
From: florian <florian@freepascal.org>
Date: Sat, 30 Jan 2021 22:47:38 +0000
Subject: [PATCH]   * additional fix for r48449

git-svn-id: trunk@48461 -
---
 compiler/nmem.pas | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/compiler/nmem.pas b/compiler/nmem.pas
index 2f2851f249..00621ecfaf 100644
--- a/compiler/nmem.pas
+++ b/compiler/nmem.pas
@@ -938,6 +938,7 @@ implementation
          htype,elementdef,elementptrdef : tdef;
          newordtyp: tordtype;
          valid : boolean;
+         minvalue, maxvalue: Tconstexprint;
       begin
          result:=nil;
          typecheckpass(left);
@@ -1054,10 +1055,19 @@ implementation
                         begin
                           { in case of an integer type, we need a new type which covers declaration range and index range,
                             see tests/webtbs/tw38413.pp
+
+                            This matters only if we sign extend, if the type exceeds the sint range, we can fall back only
+                            to the index type
                           }
-                          if is_integer(right.resultdef) then
-                            newordtyp:=range_to_basetype(min(TConstExprInt(Tarraydef(left.resultdef).lowrange),torddef(right.resultdef).low),
-                              max(TConstExprInt(Tarraydef(left.resultdef).highrange),torddef(right.resultdef).high))
+                          if is_integer(right.resultdef) and ((torddef(right.resultdef).low<0) or (TConstExprInt(Tarraydef(left.resultdef).lowrange)<0)) then
+                            begin
+                              minvalue:=min(TConstExprInt(Tarraydef(left.resultdef).lowrange),torddef(right.resultdef).low);
+                              maxvalue:=max(TConstExprInt(Tarraydef(left.resultdef).highrange),torddef(right.resultdef).high);
+                              if maxvalue>torddef(sinttype).high then
+                                newordtyp:=Torddef(right.resultdef).ordtype
+                              else
+                                newordtyp:=range_to_basetype(minvalue,maxvalue);
+                            end
                           else
                             newordtyp:=Torddef(right.resultdef).ordtype;
                         end
@@ -1068,6 +1078,7 @@ implementation
                                                          int64(Tarraydef(left.resultdef).highrange),
                                                          true
                                                         ));
+                     printnode(self);
                    end
                  else
                    begin