[Bug 2039] New: read float bug in scanf.h in msvcrt.dll.so

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=2039

Summary: read float bug in scanf.h in msvcrt.dll.so
           Product: Wine
           Version: 20040213
          Platform: PC
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: wine-misc
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

Hi,

my name is Elmar Knittel ([e-mail]), 
and I might have found a little bug in wine :(

I have got SuSE Linux 8.2 personal and 
wine-20040213-SuSELinux82.i586.rpm and 
wine-20040213-SuSELinux82.src.rpm from 
sourceforge.net/projects/wine.

There seems to be problem within the scan functions 
in wine-20040213/dlls/msvcrt/scanf.h, line 265/266:

/* get first digit. */ 
    if (!_ISDIGIT_(nch)) break;

break is triggered by decimals without leading digit, e.g:

//--------------------------------------------------------------------- 
    // 
    //	test.c - compile with MinGW under WIN32 
    // 
    //	DEPEND	= test.c 
    //	SHRINK	= upx --best --crp-ms=999999 --nrv2b 
    //	CFLAGS	= -s -Os -ffast-math -DNDEBUG -mconsole -march=pentium4 
    //	EXE	= test.exe 
    //	CC	= gcc 
    // 
    //	.PHONY: $(EXE) 
    //	$(EXE):	$(DEPEND) 
    //	$(CC) $(CFLAGS) $? -o$@ 
    //	$(SHRINK) $@ 
    // 
    //---------------------------------------------------------------------

#include <stdio.h>

int main() 
    { 
     int i; 
     static float r,g,b; 
     const char *s = "0 .7 0";

printf("\n\tBefore: r = %f, g = %f, b = %f",r,g,b);

i = sscanf(s,"%f %f %f",&r,&g,&b);

printf("\n\tAfter : r = %f, g = %f, b = %f",r,g,b); 
     printf("\n\tBackgroundColorString is: `%s`, Return is: %i\n\n",s,i);

return 0; 
    } 
    //---------------------------------------------------------------------

The output of <wine test> should be:

Before: r = 0.000000, g = 0.000000, b = 0.000000 
    After : r = 0.000000, g = 0.700000, b = 0.000000 
    BackgroundColorString is: `0 .7 0`, Return is: 3

but actually is:

Before: r = 0.000000, g = 0.000000, b = 0.000000 
    After : r = 0.000000, g = 0.000000, b = 0.000000 
    BackgroundColorString is: `0 .7 0`, Return is: 1

where the value of g in line 2 has not changed to 0.700000 
and the return value of the sscanf function is 1, not 3.

A possible solution might be to insert:

if (nch == '.') { 
    	cur = 0; 
    	goto HANDLE_DECIMALS; 
    }

directly after /* get first digit. */ 
in line 265 of original scanf.h and:

HANDLE_DECIMALS:

directly after /* handle decimals */ 
in line 276 of original scanf.h.

Probably not the best solution, but it works.

By the way; How do I manage to compile *only* 
msvcrt.dll.so? I tried make in the msvcrt-dir, 
but just the seperate object files were gene- 
rated, not the whole library... so I had to 
compile the complete wine-suit in order to 
get my patched msvcrt.dll.so ;}

Please, drop me a line, if there is a more 
simple way to get a single library. Thanks.

With best regards,

Elmar Knittel, [e-mail]