fix colon in bash completion

[godlikejay]

If bash-completion takes colon as a word breaker, ${COMP_WORDS[COMP_CWORD]} will not get the complete nose search path.

This pull request detects if colon is used for a breaker, and adds the previous word into the final parameter to nosecomplete.

[alonho]

that's what __ltrim_colon_completions is trying to solve. can you show me an example where it doesn't work?

[godlikejay]

@alonho __ltrim_colon_completions will only trim the leading filename before the colon, it is used to filter the COMPREPLY. But my patch is to make nosecomplete get the full search path.

For example, when try to complete the following cmd:

nosetests test_file.py:test_<TAB>

On my ubuntu, bash 4.2, with $COMP_WORDBREAKS including :, the COMP_WORDS is ( 'nosetests' 'test_file.py' ':' 'test_' ), so that ${COMP_WORDS[COMP_CWORD]} will only get test_, which is different from the expected test_file.py:test_ for nosecomplete.

My patch will try to join COMP_WORDS broken by : back, in the above case, $cur would be corrected to test_file.py:test_.

And one more thing about __ltrim_colon_completions, suppose COMREPLY as ( 'test_file.py:test_1' 'test_file.py:test_2' ), after __ltrim_colon_completions is executed, COMREPLY will be updated as ( 'test_1' 'test_2' ) for further completion.