CXTPPropertyGridItemDouble::StringToDouble() fails

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   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,

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
fleg Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 11 July 2012 Status: Offline Points: 46	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,

agontarenko Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 25 March 2016 Status: Offline Points: 291	Post Options Post Reply Quote agontarenko Report Post Thanks(0) Quote Reply Posted: 21 November 2024 at 4:17am
	Hello, I've increased buffer size to 32. Regards, Artem Gontarenko

fleg Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 11 July 2012 Status: Offline Points: 46	Post Options Post Reply Quote fleg Report Post Thanks(0) Quote Reply Posted: 22 hours 40 minutes ago at 3:30am
	Thanks!