New submission from Trent Mick:
When comparing content with difflib, if the resulting diff covers the
last line of one or both of the inputs that that line doesn't end with
an end-of-line character(s), then the generated diff lines don't include
an EOL. Fair enough.
Naive (and I suspect typical) usage of difflib.unified_diff(...) is:
diff = ''.join(difflib.unified_diff(...))
This results in an *incorrect* unified diff for the conditions described
above.
>>> from difflib import *
>>> gen = unified_diff("one\ntwo\nthree".splitlines(1),
... "one\ntwo\ntrois".splitlines(1))
>>> print ''.join(gen)
---
+++
@@ -1,3 +1,3 @@
one
two
-three+trois
The proper behaviour would be:
>>> gen = unified_diff("one\ntwo\nthree".splitlines(1),
... "one\ntwo\ntrois".splitlines(1))
>>> print ''.join(gen)
---
+++
@@ -1,3 +1,3 @@
one
two
-three
\ No newline at end of file
+trois
\ No newline at end of file
I *believe* that "\ No newline at end of file" are the appropriate
markers -- that tools like "patch" will know how to use. At least this
is what "svn diff" generates.
I'll try to whip up a patch.
Do others concur that this should be fixed?
----------
components: Library (Lib)
messages: 62543
nosy: trentm
severity: normal
status: open
title: naive use of ''.join(difflib.unified_diff(...)) results in bogus diffs
with inputs that don't end with end-of-line char
type: behavior
versions: Python 2.5
__________________________________
Tracker <[EMAIL PROTECTED]>
<http://bugs.python.org/issue2142>
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