From d7ba09f5432fed805603c776afb6770daf65bb53 Mon Sep 17 00:00:00 2001
From: florian <florian@freepascal.org>
Date: Fri, 7 Aug 2020 21:43:00 +0000
Subject: [PATCH]   * insert type casts when creating new unaryminus nodes
 during simplification, resolves #37508

git-svn-id: trunk@46309 -
---
 .gitattributes          |  1 +
 compiler/nadd.pas       | 10 +++++-----
 tests/webtbs/tw37508.pp |  6 ++++++
 3 files changed, 12 insertions(+), 5 deletions(-)
 create mode 100644 tests/webtbs/tw37508.pp

diff --git a/.gitattributes b/.gitattributes
index 6bf8a1c5fb..86ae8c01c3 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -18410,6 +18410,7 @@ tests/webtbs/tw37449.pp svneol=native#text/pascal
 tests/webtbs/tw37468.pp svneol=native#text/pascal
 tests/webtbs/tw37477.pp svneol=native#text/pascal
 tests/webtbs/tw37493.pp svneol=native#text/pascal
+tests/webtbs/tw37508.pp svneol=native#text/pascal
 tests/webtbs/tw3751.pp svneol=native#text/plain
 tests/webtbs/tw3758.pp svneol=native#text/plain
 tests/webtbs/tw3764.pp svneol=native#text/plain
diff --git a/compiler/nadd.pas b/compiler/nadd.pas
index 494121afb9..87a17ee985 100644
--- a/compiler/nadd.pas
+++ b/compiler/nadd.pas
@@ -737,7 +737,7 @@ implementation
               begin
                 case nodetype of
                   muln:
-                   result := cunaryminusnode.create(left.getcopy);
+                   result := ctypeconvnode.create_internal(cunaryminusnode.create(left.getcopy),left.resultdef);
                   else
                     ;
                 end;
@@ -818,9 +818,9 @@ implementation
               begin
                 case nodetype of
                   addn,orn,xorn:
-                   result := right.getcopy;
+                    result := right.getcopy;
                   subn:
-                   result := cunaryminusnode.create(right.getcopy);
+                    result := ctypeconvnode.create_internal(cunaryminusnode.create(right.getcopy),right.resultdef);
                   andn,muln:
                     begin
                       if (cs_opt_level4 in current_settings.optimizerswitches) or
@@ -844,7 +844,7 @@ implementation
               begin
                 case nodetype of
                   muln:
-                   result := cunaryminusnode.create(right.getcopy);
+                   result := ctypeconvnode.create_internal(cunaryminusnode.create(right.getcopy),right.resultdef);
                   else
                     ;
                 end;
@@ -976,7 +976,7 @@ implementation
                           end;
                       subn:
                         begin
-                          result:=cunaryminusnode.create(right.getcopy);
+                          result:=ctypeconvnode.create_internal(cunaryminusnode.create(right.getcopy),right.resultdef);
                           exit;
                         end;
                       else
diff --git a/tests/webtbs/tw37508.pp b/tests/webtbs/tw37508.pp
new file mode 100644
index 0000000000..27c5c9c353
--- /dev/null
+++ b/tests/webtbs/tw37508.pp
@@ -0,0 +1,6 @@
+{ %OPT=-O3 }
+var a, b : integer;
+begin
+  b := 0;
+  b := b - a - a { `b := b - a` won't trigger the error }
+end.