Sorry:  I should have said my hand-renaming the class in the .cs *may* be the cause of what you found, but not that it necessarily *is* the cause of what you found.

Thanks,
Tim

On Jul 4, 2018, at 10:59 PM, Tim Johnson wrote:

> Hi Bob & David,
> 
> Thanks for all your help with this.
> 
> The runs are short because in my original fileOut, the class was named MoodleClient, but I hand-edited the .cs to rename it FooClient and to remove all my proprietary methods I'm not yet ready to share.
> 
> I did try to explain this in my original post which is now in the distant realm of the thread.  :)
> 
> Best,
> Tim
> 
> On Jul 4, 2018, at 3:55 PM, Bob Arning wrote:
> 
>> A little more...
>> 
>> This problem may ultimately be due to something broken in the text being displayed. If I look at the funky class comment, it has these runs
>> 
>> a RunArray runs: #(1 35 18 20 3) values: {#() . {a TextFontChange font: 1} . #() . {a TextEmphasis code: 1} . #()}
>> 
>> The total length of the run sizes is 77, yet the string is only 70 bytes long.
>> 
>> If I copy that text out and paste into a workspace, the runs now look like:
>> 
>> a RunArray runs: #(1 35 18 16) values: {#() . {a TextFontChange font: 1} . #() . {a TextEmphasis code: 1}}
>> 
>> and the size of the runs matches the size of the string at 70. I wonder if other occurrences of this problem might have a similar cause.
>> 
>> On 7/4/18 4:20 PM, David T. Lewis wrote:
>>> On Wed, Jul 04, 2018 at 03:46:16PM -0400, Bob Arning wrote:
>>>> Here is a side-by-side comparison with the styled version on the right 
>>>> and the same text unstyled on the left. Note the difference in runStopIndex
>>>> 
>>> I see it now. Thanks!
>>> 
>>> Dave
>>> 
>>> 
>>>> On 7/4/18 2:49 PM, David T. Lewis wrote:
>>>>> I tried reverting #scanCharactersFrom:to:in:rightX:stopConditions:kern:
>>>>> to the earlier version (cmm 6/12/2010 11:52), but I still get failures
>>>>> with cursor and mouse in the class comment text when browsing the FooClient
>>>>> class. There must be something else going on here, and it is certainly
>>>>> not obvious to me why it is happening only with the FooClient test
>>>>> example.
>>>>> 
>>>>> Dave
>>>>> 
>>>>> On Wed, Jul 04, 2018 at 02:10:00PM -0400, Bob Arning wrote:
>>>>>> perhaps this will help:
>>>>>> 
>>>>>> This version does not seem to exhibit the error and it limits stopIndex
>>>>>> to the size of the string
>>>>>> 
>>>>>> !CharacterScanner methodsFor: 'scanning' stamp: 'cmm 6/12/2010 11:52'!
>>>>>> scanCharactersFrom: startIndex to: stopIndex in: sourceString rightX:
>>>>>> rightX stopConditions: stops kern: kernDelta
>>>>>> 
>>>>>> ?????? | startEncoding selector |
>>>>>> ?????? (sourceString isByteString) ifTrue: [^ self
>>>>>> basicScanCharactersFrom: startIndex *to: (stopIndex min: sourceString
>>>>>> size)* in: sourceString rightX: rightX stopConditions: stops kern:
>>>>>> kernDelta.].
>>>>>> 
>>>>>> ?????? (sourceString isWideString) ifTrue: [
>>>>>> ?????? ?????? startIndex > stopIndex ifTrue: [lastIndex := stopIndex. ^
>>>>>> stops endOfRun].
>>>>>> ?????? ?????? startEncoding :=?? (sourceString at: startIndex) 
>>>>>> leadingChar.
>>>>>> ?????? ?????? selector := EncodedCharSet scanSelectorAt: startEncoding.
>>>>>> ?????? ?????? ^ self perform: selector withArguments: (Array with:
>>>>>> startIndex with: stopIndex with: sourceString with: rightX with: stops
>>>>>> with: kernDelta).
>>>>>> ?????? ].
>>>>>> 
>>>>>> ?????? ^ stops endOfRun
>>>>>> ! !
>>>>>> 
>>>>>> This version fails and does not limit the stopIndex.
>>>>>> 
>>>>>> !CharacterScanner methodsFor: 'scanning' stamp: 'nice 10/22/2013 20:49'!
>>>>>> scanCharactersFrom: startIndex to: stopIndex in: sourceString rightX:
>>>>>> rightX
>>>>>> ?????? ^sourceString scanCharactersFrom: startIndex *to: stopIndex* with:
>>>>>> self rightX: rightX font: font! !
>>>>>> 
>>>>>> 
>>>>>> On 7/4/18 11:53 AM, David T. Lewis wrote:
>>>>>>> On Wed, Jul 04, 2018 at 02:35:59PM +0200, karl ramberg wrote:
>>>>>>>> On Wed, Jul 4, 2018 at 11:10 AM K K Subbu <kksubbu.ml at gmail.com> wrote:
>>>>>>>> 
>>>>>>>>> On Tuesday 03 July 2018 04:40 AM, Tim Johnson wrote:
>>>>>>>>>> 1. File-in the .cs as attached*.
>>>>>>>>>> 2. In a system browser, click on the class, then click on the [?] 
>>>>>>>>>> button
>>>>>>>>>> to view class comment.
>>>>>>>>>> 3. Notice the styled text in the comment.
>>>>>>>>>> 4. Click around the comment pane a bit.
>>>>>>>>>> 5. Eventually, see "Error: subscript is out of bounds: 71" appear over
>>>>>>>>>> and over until you interrupt.
>>>>>>>>> In step 4, it is sufficient to click once near the bottom of the pane
>>>>>>>>> when the cursor changes from I-bar to arrow and then wait. This will
>>>>>>>>> trigger the error, but the error window triggers itself recursively
>>>>>>>>> around 50 times before stopping and displaying the windows.
>>>>>>>>> 
>>>>>>>>> I added an assert to catch it before recursion:
>>>>>>>>> 
>>>>>>>>>     self assert: lastIndex < sourceString size.
>>>>>>>>> 
>>>>>>>>> The assert window itself throws up another error, but that is a topic
>>>>>>>>> for another thread ;-).
>>>>>>>>> 
>>>>>>>>> Regards .. Subbu
>>>>>>>> Hi,
>>>>>>>> See class comment i NewParagraph for a hint of what happens.
>>>>>>>> A empty lineSpan 71 to: 70 is added to the end of the paragraph, when 
>>>>>>>> you
>>>>>>>> double click below the text.
>>>>>>>> When the character scanner looks for characters outside of the string at
>>>>>>>> index 71 it cause a recursion.
>>>>>>>> 
>>>>>>>> Best,
>>>>>>>> Karl
>>>>>>>> 
>>>>>>> Good tiip to look at the NewParagraph class comment, there is apparently
>>>>>>> some left over messiness in here somewhere.
>>>>>>> 
>>>>>>> Another way to trigger the bug using the test case with FooClient is
>>>>>>> to position the cursor in the comment pane and use keyboard right cursor
>>>>>>> to move to the end of the comment. This causes the same bounds error but
>>>>>>> takes a different path through the code leading to the error.
>>>>>>> 
>>>>>>> Looking through the stack in a debugger after triggering the error with
>>>>>>> the mouse, here are a few notes (but no conclusions):
>>>>>>> 
>>>>>>> On mouseUp: we enter Editor>>selectWord then call
>>>>>>> Editor>>selectWordLeftDelimiters:rightDelimiters:
>>>>>>> which has this:
>>>>>>> 
>>>>>>> 	"Select the whole text when clicking before first or after last
>>>>>>> 	character"
>>>>>>> 	(here > string size or: [here < 2]) ifTrue: [^self selectFrom: 1 to:
>>>>>>> 	string size].
>>>>>>> 
>>>>>>> where string is the 70 character String derived from the Text.
>>>>>>> 
>>>>>>> At this point we are trying to select from 1 to 70 (the whole string for
>>>>>>> the entire text) in TextEditor>>selectFrom:to:
>>>>>>> 
>>>>>>> This calls Editor>>selectInvisiblyFrom:to: and here the stop index is
>>>>>>> set past the size of the string:
>>>>>>> 
>>>>>>>   selectInvisiblyFrom: start to: stop
>>>>>>>      "Select the designated characters, inclusive.  Make no visual
>>>>>>>      changes."
>>>>>>> 
>>>>>>>      self markIndex: start pointIndex: stop + 1
>>>>>>> 
>>>>>>> From this point we are trying to go from index 1 to index 71 over a 
>>>>>>> string
>>>>>>> of size 70, and eventually end up with the out of bounds exception.
>>>>>>> 
>>>>>>> A clue that this might be accumulation of kludges: Looking at senders of
>>>>>>> selectInvisiblyFrom:to: (such as TextEditor>>addText:event:) shows a 
>>>>>>> number
>>>>>>> of methods that subtract 1 from the stop index when before calling the
>>>>>>> method
>>>>>>> that adds 1 back to the stop index. This certainly does not have a good
>>>>>>> smell.
>>>>>>> 
>>>>>>> It is not clear to me why selectInvisiblyFrom:to: would be adding one to
>>>>>>> the
>>>>>>> stop index, but I see that the method stamp is jmv 5/27/2011, which
>>>>>>> suggests
>>>>>>> to me that we should take a look at Cuis to figure out how this is 
>>>>>>> intended
>>>>>>> to function. Cuis does not show any cases of senders of
>>>>>>> selectInvisiblyFrom:to:
>>>>>>> that subtract 1 from the stop index, and the Cuis implementation of
>>>>>>> selectInvisiblyFrom:to: is that same as Squeak.
>>>>>>> 
>>>>>>> Dave
>>>>>>> 
>>>>>>> 
>>>> 
>> 
>> 
> 
> 

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