From 26cc281390a62be1627edbb7b18fefdeacd687c6 Mon Sep 17 00:00:00 2001
From: Jonas Maebe <jonas@freepascal.org>
Date: Sat, 10 Jul 2010 12:15:13 +0000
Subject: [PATCH]   * fixed real48 to double conversion for 0.0 (patch by
 "jeng", mantis #16863)

git-svn-id: trunk@15543 -
---
 .gitattributes          | 1 +
 rtl/inc/genmath.inc     | 7 +++++++
 tests/webtbs/tw16863.pp | 8 ++++++++
 3 files changed, 16 insertions(+)
 create mode 100644 tests/webtbs/tw16863.pp

diff --git a/.gitattributes b/.gitattributes
index 57bb17c496..0e2d4b8ee9 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -10527,6 +10527,7 @@ tests/webtbs/tw16803.pp svneol=native#text/plain
 tests/webtbs/tw1681.pp svneol=native#text/plain
 tests/webtbs/tw16820.pp svneol=native#text/plain
 tests/webtbs/tw16861.pp svneol=native#text/plain
+tests/webtbs/tw16863.pp svneol=native#text/plain
 tests/webtbs/tw16874.pp svneol=native#text/plain
 tests/webtbs/tw1696.pp svneol=native#text/plain
 tests/webtbs/tw1699.pp svneol=native#text/plain
diff --git a/rtl/inc/genmath.inc b/rtl/inc/genmath.inc
index 29ebf3a421..fd3d7c3dcf 100644
--- a/rtl/inc/genmath.inc
+++ b/rtl/inc/genmath.inc
@@ -1403,6 +1403,13 @@ function fpc_int64_to_double(i : int64): double; compilerproc;
          exponent : word;
 
       begin
+         { check for zero }
+         if r[0]=0 then
+           begin
+             real2double:=0.0;
+             exit;
+           end;
+
          { copy mantissa }
          res[0]:=0;
          res[1]:=r[1] shl 5;
diff --git a/tests/webtbs/tw16863.pp b/tests/webtbs/tw16863.pp
new file mode 100644
index 0000000000..8132bacd82
--- /dev/null
+++ b/tests/webtbs/tw16863.pp
@@ -0,0 +1,8 @@
+var
+    d : double;
+    r : real48 = ($0, $0, $0, $0, $0, $0); 
+BEGIN
+    d := r;
+    if d<>0.0 then
+      halt(1);
+END.