how to reduce bugs due to incorrect indentation

[Larry Martell]

On Thu, Feb 6, 2014 at 3:29 PM, Roel Schroeven <roel at roelschroeven.net> wrote:
> msustik at gmail.com schreef:
>>
>> I had a bug in a Python script recently. The code in question was
>> something along the lines of:
>>
>> if a == 1:
>>     x = y
>> else:
>>     x = z
>> y = z + y
>> z = z + 1
>>
>> While editing this file I accidentally pushed TAB on the line with 'y = z
>> + y'.
>>
>> My changes were elsewhere and I did not notice the above one line change
>> when I looked at the diffs before commit. I should have noticed it...
>>
>> It was rare that a was 1 and therefore the problem did not show up for a
>> while. (I know I should have had tests exercising all cases...)
>>
>> When the bug showed up, it was kind of difficult to remember what was the
>> original intent. Fortunately, looking at old versions allowed me to find the
>> problem commit and the bug.
>>
>> Any suggestion on how to avoid this type of error in the future?
>
>
> My suggestion: configure your editor to insert the appropriate amount of
> spaces instead of a tab when you press the tab key.

+1 - tabs are evil.