CXTPPropertyGridItemDouble::StringToDouble() fails

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   Hi,
I probably found a failure in CXTPPropertyGridItemDouble::StringToDouble() method.
With some value where the string is > 20 char, the value we get  is incorrect.

Example:
with "1.3856932626629e-04" no problem the item shows with precision I asked "-1.3857 E-4"
; but same as negative "-1.3856932626629E-04" (21 chars)
get truncated to 20 chars, so "-1.3856932626629E-0" get converted to "-1.3857" losing the exponent.

Looking at the code (version 24.0.0), this buffer of 20 chars looks suspicious. 

    char astring[20];
    WideCharToMultiByte(CP_ACP, 0, strValue, -1, astring, 20, NULL, NULL);
    return (double)atof(astring);

from definition of limit of double that goes from -DBL_MIN to DBL_MAX 
DBL_MAX 1.7976931348623158e+308
-DBL_MIN -2.2250738585072014e-308

buffer should be at least 25 chars.
you can reproduce the problem with sample app PropertyGrid.PropertyGrid.exe

Can you consider a fix for next release?

Also, as mentioned here
https://forum.codejock.com/cxtppropertygriditemdoublestringtodouble_topic12540_post42376.html?KW=StringTodouble#42376 
It could be good to have this method virtual.

Thanks,

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fleg Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 11 July 2012 Status: Offline Points: 45	Post Options Post Reply Quote fleg Report Post Thanks(0) Quote Reply Topic: CXTPPropertyGridItemDouble::StringToDouble() fails Posted: 06 November 2024 at 11:33am
	Hi, I probably found a failure in CXTPPropertyGridItemDouble::StringToDouble() method. With some value where the string is > 20 char, the value we get is incorrect. Example: with "1.3856932626629e-04" no problem the item shows with precision I asked "-1.3857 E-4" ; but same as negative "-1.3856932626629E-04" (21 chars) get truncated to 20 chars, so "-1.3856932626629E-0" get converted to "-1.3857" losing the exponent. Looking at the code (version 24.0.0), this buffer of 20 chars looks suspicious. char astring[20]; WideCharToMultiByte(CP_ACP, 0, strValue, -1, astring, 20, NULL, NULL); return (double)atof(astring); from definition of limit of double that goes from -DBL_MIN to DBL_MAX DBL_MAX 1.7976931348623158e+308 -DBL_MIN -2.2250738585072014e-308 buffer should be at least 25 chars. you can reproduce the problem with sample app PropertyGrid.PropertyGrid.exe Can you consider a fix for next release? Also, as mentioned here https://forum.codejock.com/cxtppropertygriditemdoublestringtodouble_topic12540_post42376.html?KW=StringTodouble#42376 It could be good to have this method virtual. Thanks,