OpenEuphoria

1. eugrid 1.3.4 bug (attn Phil Russell)

• Posted by marky1124 Apr 21, 2009
• 832 views

Hi,

I have found a bug that crashes eugrid v1.3.4. It can be demonstrated by running the radiobutton_demo.exw sample program that comes with eugrid. Here are the steps to demonstrate the crash:-

1. Run radiobutton_demo.exw
2. Press and hold the left mouse button down on the top radio button
3. Press the down arrow until the line you have clicked on scrolls out of sight (you can also use a mouse wheel to do this)
4. Let go of the left mouse button.

It will now crash with

C:\Documents and Settings\Administrator\My Documents\$USER\T40 Desktop\Euphoria\ 
eugrid134\eugrid.ew:3536 in function EGW_OnLeftMouseUp() 
subscript value 0 is out of bounds, reading from a sequence of length 36 
 
... called from C:\Documents and Settings\Administrator\My Documents\Euphoria\eugrid134\eugrid.ew:4924 in function EGW_OnGridEvent() 
 
^^^ call-back from Windows 
 
... called from c:\euphoria\win32lib\Include\w32dll.ew:280 in procedure w32Proc() 
 
... called from c:\euphoria\win32lib\Include\win32lib.ew:24845 in procedure eventLoop() 
 
... called from c:\euphoria\win32lib\Include\win32lib.ew:25073 in procedure WinMain() 
 
... called from C:\Documents and Settings\Administrator\My Documents\Euphoria\eugrid134\radiobutton_demo.exw:113 
 
--> See ex.err 
 
Press Enter... 

I believe I have found the cause of the problem in eugrid.ew (line 3536). I think the condition needs an extra set of brackets:

                -- If not a checkbox cell then notify select button up here 
                if index > 0 and column <=0 or (column>0 
                and not find(GridDraw[grid][CELLS][index][EGW_CELL_TYPE], {EGW_CHECKBOX, EGW_RADIOBUTTON})) then 

Should be changed to

                -- If not a checkbox cell then notify select button up here 
                -- 21/04/09 - Mwy - Fixed condition to cope with index=0 & column=1 
                if index > 0 and 
                	(column <=0 or 
                	(column>0 and not find(GridDraw[grid][CELLS][index][EGW_CELL_TYPE], {EGW_CHECKBOX, EGW_RADIOBUTTON}))) 
            	then 

I've tested my code fix and it defintely gets rid of the crash. I can't say I understand the eugrid source well enough to be 100% sure that I've done exactly the right thing. Hopefully I've not exchanged one obvious bug for a much more subtle and devious one.

I hope Phil Russell sees this.

Best Regards,
Mark Young