Fix for issue1488943 - difflib.Differ() doesn't always add hints for tab
characters.
diff --git a/Lib/difflib.py b/Lib/difflib.py
index 679bd2a..b43dc97 100644
--- a/Lib/difflib.py
+++ b/Lib/difflib.py
@@ -1061,20 +1061,21 @@
Example:
>>> d = Differ()
- >>> results = d._qformat('\tabcDefghiJkl\n', '\t\tabcdefGhijkl\n',
- ... ' ^ ^ ^ ', '+ ^ ^ ^ ')
+ >>> results = d._qformat('\tabcDefghiJkl\n', '\tabcdefGhijkl\n',
+ ... ' ^ ^ ^ ', ' ^ ^ ^ ')
>>> for line in results: print repr(line)
...
'- \tabcDefghiJkl\n'
'? \t ^ ^ ^\n'
- '+ \t\tabcdefGhijkl\n'
- '? \t ^ ^ ^\n'
+ '+ \tabcdefGhijkl\n'
+ '? \t ^ ^ ^\n'
"""
# Can hurt, but will probably help most of the time.
common = min(_count_leading(aline, "\t"),
_count_leading(bline, "\t"))
common = min(common, _count_leading(atags[:common], " "))
+ common = min(common, _count_leading(btags[:common], " "))
atags = atags[common:].rstrip()
btags = btags[common:].rstrip()
diff --git a/Lib/test/test_difflib.py b/Lib/test/test_difflib.py
index 011ef17..93f5c74 100644
--- a/Lib/test/test_difflib.py
+++ b/Lib/test/test_difflib.py
@@ -20,6 +20,14 @@
diff_gen = difflib.unified_diff([], [])
self.assertRaises(StopIteration, diff_gen.next)
+ def test_added_tab_hint(self):
+ # Check fix for bug #1488943
+ diff = list(difflib.Differ().compare(["\tI am a buggy"],["\t\tI am a bug"]))
+ self.assertEqual("- \tI am a buggy", diff[0])
+ self.assertEqual("? --\n", diff[1])
+ self.assertEqual("+ \t\tI am a bug", diff[2])
+ self.assertEqual("? +\n", diff[3])
+
patch914575_from1 = """
1. Beautiful is beTTer than ugly.
2. Explicit is better than implicit.
diff --git a/Misc/NEWS b/Misc/NEWS
index d661640..356e3a1 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -476,6 +476,8 @@
Library
-------
+- Issue #1488943: difflib.Differ() doesn't always add hints for tab characters
+
- Issue #6123: tarfile now opens empty archives correctly and consistently
raises ReadError on empty files.