Re: FIXED - FT2: Error in FT_Done_Library()?

[Jack Davis]

Hi David,

Your fixes in the latest download seem to work great - thanks for the quick 
turnaround!

-Jack



At 04:21 PM 2/21/2000 +0100, David Turner wrote:
>Hello Jack,
>
>Thanks a lot for reporting this error. Actually, I wasn't aware of this 
>problem,
>and it wasn't the reason for not calling FT_Done_FreeType in "ftview" (the bug
>was introduced with the latest change of the TrueType glyph loader, which is 
>way
>more recent :-)
>
>I have found the bug and commited the fix to the CVS repository. It involved
>modifying several files because I partially re-designed a few things in the
>way.
>
>I have also added a new demo program called "demos/src/memtest.c" which is
>derived from the one you sent us. Basically, it shows how to hook a custom
>memory manager to the FreeType library. (Note that it is not compiled by
>defaulted, simply because it includes hard-coded font paths that I don't
>want in the "clean" demos).
>
>Note that the functions "FT_New_Library" and "FT_Default_Drivers" are not
>public yet though, but it gives a pretty good idea on how to do it..
>
>Again, thanks
>
>- David
>
>Jack Davis a écrit :
> > 
> > Hi David/Werner,
> > 
> > I am getting a Windows system error when FT_Done_Library() apparently tries 
> > to free an invalid memory block.  I've reduced my test to a 7 line
> > program that produces the error if FT_Load_Glyph() is called (see below, a 
> > file copy also attached).
> > 
> > I noticed that the demo\ftview.c sample program does not call 
> > FT_Done_Library (?! - only TF_Done_Face() is called).  Is this a problem 
> > you are aware
> > of?  For this test I'm compiling as a console app using Visual C++ v6 and 
> > building my FT2 library from sources downloaded on 2/17.  Has anyone else
> > using Visual C experienced this problem?
> > 
> > Thanks,
> > Jack
> > 
> > In stepping through the program, all FT2 functions return with 0 until the 
> > memory exception in FT_Done_Library() is encountered.  If the call to
> > FT_Load_Glyph() is commented out, everything runs properly and even 
> > FT_Done_Library() returns with a normal 0 result.
> > 
> > /* ft2test1.cpp */
> > 
> > #include "stdafx.h"
> > #include <freetype.h>
> > 
> > int APIENTRY WinMain(HINSTANCE hInstance,
> >                      HINSTANCE hPrevInstance,
> >                      LPSTR     lpCmdLine,
> >                      int       nCmdShow)
> > {
> >     FT_Library  library;
> >     FT_Face     face;
> >     int         glyphIndex;
> >     int         result;
> > 
> >     result = FT_Init_FreeType( &library );
> > 
> >     result = FT_New_Face( library, "arial.ttf", 0, &face );
> > 
> >     result = FT_Set_Char_Size( face, 0, 16*64, 96, 96 );
> > 
> >     glyphIndex = FT_Get_Char_Index( face, (int)'A' );
> > 
> >     /* memory error occurs in FT_DoneFreeType() if FT_Load_Glyph() is 
> > called */
> >     result = FT_Load_Glyph(face, glyphIndex, FT_LOAD_DEFAULT );
> > 
> >     result = FT_Done_Face( face );
> > 
> >     result = FT_Done_FreeType( library );
> > 
> >     return 0;
> > }
> > 
> > The call stack sequence when the error occurs appears as follows:
> > 
> > free(void * 0x007a5090) line 926 + 11 bytes
> > ft_free(FT_MemoryRec_ * 0x007a03d0, void * 0x007a5090) line 143 + 9 bytes
> > FT_Free(FT_MemoryRec_ * 0x007a03d0, void * * 0x007a45d0) line 206 + 18 bytes
> > TT_Done_GlyphZone(FT_MemoryRec_ * 0x007a03d0, TT_GlyphZone_ * 0x007a45c0) 
> > line 109 + 16 bytes
> > TT_Destroy_Context(TT_ExecContextRec_ * 0x007a4560, FT_MemoryRec_ * 
> > 0x007a03d0) line 386 + 19 bytes
> > TT_Done_Driver(TT_DriverRec_ * 0x007a0170) line 931 + 22 bytes
> > Destroy_Driver(FT_DriverRec_ * 0x007a0170) line 376 + 12 bytes
> > FT_Done_Library(FT_LibraryRec_ * 0x007a02e0) line 721 + 9 bytes
> > FT_Done_FreeType(FT_LibraryRec_ * 0x007a02e0) line 2509 + 9 bytes
> > 
> >    ft2test1.cppName: ft2test1.cpp
> >                Type: Plain Text (text/plain)