On Wed, 31 Mar 2010, Levente Uzonyi wrote:

> On Wed, 31 Mar 2010, Andreas Raab wrote:
>
>> Hi -
>> 
>> I was just trying to implement the code for condensing the changes to the 
>> end of the sources file and ran into some 'interesting' issues. I would 
>> expect this to work:
>> 
>> fullName := 'test1.sources'.
>> "Copy sources file; change file name accordingly"
>> FileStream forceNewFileNamed: fullName do:[:newFile|
>> 	sourcesFile := SourceFiles at: 1.
>> 	sourcesFile position: 0.
>> 	FileDirectory default copyFile: sourcesFile toFile: newFile.
>> 	newFile position = sourcesFile size ifFalse:[self error: 'File copy 
>> failed'].
>> ].
>
> This one is definitely a bug. Using a readOnlyCopy instead of the original 
> sources file makes debugging a bit easier. :)

Okay, found the cause of the issue. MultiByteFileStream doesn't implement 
it's own version of #nextInto: which is used by #copyFile:toFile:, 
therefore the file is not decoded. Replacing #nextInto: with an 
appropriate #next: send passes the test.

Implementing MultiByteFileStream >> #nextInto: is a bit tricky, since if 
the argument is a ByteString, then there's a chance that the result cannot 
be stored into the buffer. In similar cases the ByteString is swapped with 
a WideString, but in this case it can become a source of bugs, since the 
sender of #nextInto: may expect that the buffer is still a ByteString.

IMHO #copyFile:toFile: shouldn't exist, it's just a utility method, 
totally unrelated to FileDirectory. It also assumes that the files are in 
"ascii" mode which is wrong.


Levente

>
>> 
>> But it fails. Then I tried something else:
>> 
>> fullName := 'test2.sources'.
>> "Copy sources file; change file name accordingly"
>> FileStream forceNewFileNamed: fullName do:[:newFile|
>> 	sourcesFile := SourceFiles at: 1.
>> 	sourcesFile position: 0.
>> 	[sourcesFile atEnd] whileFalse:[newFile nextChunkPut: sourcesFile 
>> nextChunk].
>> 	newFile position = sourcesFile size ifFalse:[self error: 'File copy 
>> failed'].
>> ].
>> 
>> That fails to. Then I tried:
>> 
>> fullName := 'test3.sources'.
>> "Copy sources file; change file name accordingly"
>> FileStream forceNewFileNamed: fullName do:[:newFile|
>> 	sourcesFile := SourceFiles at: 1.
>> 	sourcesFile position: 0.
>> 	[sourcesFile atEnd] whileFalse:[newFile nextChunkPutWithStyle: 
>> sourcesFile nextChunkText].
>> 	newFile position = sourcesFile size ifFalse:[self error: 'File copy 
>> failed'].
>> ].
>> 
>> That fails as well. Help! What am I doing wrong? How does one copy the 
>> sources file properly and why do the above methods not work?
>
> The latter two will probably fail, since the chunk reading code throws away 
> unnecessary whitespaces.
>
> I checked these in 4.0 and all three are failing the same way as in 4.1.
>
>
> Levente
>
>> 
>> Cheers,
>>  - Andreas
>> 
>> 
>
>