From 0db9ff5c39f66e967a1cd4bdaa7536877a48210e Mon Sep 17 00:00:00 2001
From: Jonas Maebe <jonas@freepascal.org>
Date: Fri, 1 Feb 2019 17:31:53 +0000
Subject: [PATCH]   * fixed packed bitsize calculation for types with a
 negative lower bound and     and upper bound just below the next power of two
 (mantis #34971)

git-svn-id: trunk@41161 -
---
 .gitattributes          |  1 +
 compiler/symdef.pas     |  8 ++++----
 tests/webtbs/tw34971.pp | 25 +++++++++++++++++++++++++
 3 files changed, 30 insertions(+), 4 deletions(-)
 create mode 100644 tests/webtbs/tw34971.pp

diff --git a/.gitattributes b/.gitattributes
index 3554d00acf..d346cb518c 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -16485,6 +16485,7 @@ tests/webtbs/tw3490.pp svneol=native#text/plain
 tests/webtbs/tw3491.pp svneol=native#text/plain
 tests/webtbs/tw3492.pp svneol=native#text/plain
 tests/webtbs/tw3494.pp svneol=native#text/plain
+tests/webtbs/tw34971.pp svneol=native#text/plain
 tests/webtbs/tw3499.pp svneol=native#text/plain
 tests/webtbs/tw3504.pp svneol=native#text/plain
 tests/webtbs/tw3506.pp svneol=native#text/plain
diff --git a/compiler/symdef.pas b/compiler/symdef.pas
index 6836510f84..502851b4ed 100644
--- a/compiler/symdef.pas
+++ b/compiler/symdef.pas
@@ -2716,8 +2716,8 @@ implementation
             if (minval>=0) then
               sizeval:=maxval
             else
-              { don't count 0 twice }
-              sizeval:=(cutils.max(-minval,maxval)*2)-1;
+             { don't count 0 twice, but take into account that range goes from -n-1..n }
+              sizeval:=(cutils.max(-minval,maxval+1)*2)-1;
             { 256 must become 512 etc. }
             nextpowerof2(sizeval+1,power);
             result := power;
@@ -2939,8 +2939,8 @@ implementation
             if (low>=0) then
               sizeval:=high
             else
-              { don't count 0 twice }
-              sizeval:=(cutils.max(-low,high)*2)-1;
+              { don't count 0 twice, but take into account that range goes from -n-1..n }
+              sizeval:=(cutils.max(-low,high+1)*2)-1;
             { 256 must become 512 etc. }
             nextpowerof2(sizeval+1,power);
             result := power;
diff --git a/tests/webtbs/tw34971.pp b/tests/webtbs/tw34971.pp
new file mode 100644
index 0000000000..7d957ba0e5
--- /dev/null
+++ b/tests/webtbs/tw34971.pp
@@ -0,0 +1,25 @@
+type
+  t1 = -1..1;
+  t2 = -4..3;
+  t3 = -3..4;
+type
+  r1 = bitpacked record
+    f: t1;
+  end;
+
+  r2 = bitpacked record
+    f: t2;
+  end;
+
+  r3 = bitpacked record
+   f: t3;
+  end;
+
+begin
+  if bitsizeof(r1.f)<>2 then
+    halt(1);
+  if bitsizeof(r2.f)<>3 then
+    halt(2);
+  if bitsizeof(r3.f)<>4 then
+    halt(3);
+end.