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LCL: Fix BMP handling issues in big endian systems. Issue #27719, patch from Mark Morgan Lloyd.

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git-svn-id: trunk@48623 -
This commit is contained in:
juha 2015-04-04 18:23:18 +00:00
parent 1c13bee866
commit d126fb4491
2 changed files with 20 additions and 9 deletions
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15
lcl/include/bitmap.inc
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@ -127,18 +127,21 @@ begin
begin begin
FillChar(Header, SizeOf(Header), 0); FillChar(Header, SizeOf(Header), 0);
{ Create a BMP header ordered as it would be on disc, noting that if the CPU
is big-endian this will be the "wrong way round" for numeric operations. }
{$IFNDEF ENDIAN_BIG}
Header.bfType := $4d42; Header.bfType := $4d42;
Header.bfSize := SizeOf(Header) + ASize; Header.bfSize := SizeOf(Header) + ASize;
{$ELSE}
Header.bfType := $424d;
Header.bfSize := swap(SizeOf(Header) + ASize);
{$ENDIF}
//Header.bfOffBits := 0; //data imediately follows //Header.bfOffBits := 0; //data imediately follows
{$IFDEF ENDIAN_BIG}
swap(Header.bfType);
swap(Header.bfSize);
//swap(Header.bfOffBits);
{$ENDIF}
S := THeaderStream.Create(AStream, @Header, SizeOf(Header)); S := THeaderStream.Create(AStream, @Header, SizeOf(Header));
try try
inherited LoadFromStream(S, Header.bfSize); inherited LoadFromStream(S, SizeOf(Header) + ASize);
finally finally
S.Free; S.Free;
end; end;

14
lcl/intfgraphics.pas
View File

@ -5047,13 +5047,21 @@ end;
function TLazReaderBMP.InternalCheck(Stream: TStream): boolean; function TLazReaderBMP.InternalCheck(Stream: TStream): boolean;
var var
BFH: TBitMapFileHeader; BFH: TBitMapFileHeader;
offbits: DWORD;
begin begin
Stream.Read(BFH, SizeOf(BFH)); Stream.Read(BFH, SizeOf(BFH));
Result := BFH.bfType = BMmagic; // Just check magic number Result := BFH.bfType = LEtoN(BMmagic); // Just check magic number
// store the data offset { Store the data offset. BFH is poorly aligned (dictated by the .bmp file
format), which can cause problems for architectures such as SPARC and some
ARM implementations which have strict alignment requirements. That is why
the code below uses an intermediate variable, rather than a direct call to
LEtoN(BFH.bfOffBits) which will try to pass a misaligned parameter. }
if Result and (BFH.bfOffBits <> 0) if Result and (BFH.bfOffBits <> 0)
then FDataOffset := Stream.Position + BFH.bfOffBits - SizeOf(BFH); then begin
offbits := BFH.bfOffBits;
FDataOffset := Stream.Position + LEtoN(offbits) - SizeOf(BFH)
end
end; end;
procedure TLazReaderBMP.InternalReadHead; procedure TLazReaderBMP.InternalReadHead;