tests/test-bdiff.py

merge: before cd/dc prompt, check that changed side really changed

Before, merging would in some cases ask "wrong" questions about
"changed/deleted" conflicts ... and even do it before the resolve phase where
they can be postponed, re"resolved" or answered in bulk operations.

Instead, check that the content of the changed file really did change.

Reading and comparing file content is expensive and should be avoided before
the resolve phase. Prompting the user is however even more expensive. Checking
the content here is thus better.

The 'f in ancestors[0]' should not be necessary but is included to be extra
safe.

import struct
from mercurial import bdiff, mpatch

def test1(a, b):
    d = bdiff.bdiff(a, b)
    c = a
    if d:
        c = mpatch.patches(a, [d])
    if c != b:
        print "***", repr(a), repr(b)
        print "bad:"
        print repr(c)[:200]
        print repr(d)

def test(a, b):
    print "***", repr(a), repr(b)
    test1(a, b)
    test1(b, a)

test("a\nc\n\n\n\n", "a\nb\n\n\n")
test("a\nb\nc\n", "a\nc\n")
test("", "")
test("a\nb\nc", "a\nb\nc")
test("a\nb\nc\nd\n", "a\nd\n")
test("a\nb\nc\nd\n", "a\nc\ne\n")
test("a\nb\nc\n", "a\nc\n")
test("a\n", "c\na\nb\n")
test("a\n", "")
test("a\n", "b\nc\n")
test("a\n", "c\na\n")
test("", "adjfkjdjksdhfksj")
test("", "ab")
test("", "abc")
test("a", "a")
test("ab", "ab")
test("abc", "abc")
test("a\n", "a\n")
test("a\nb", "a\nb")

#issue1295
def showdiff(a, b):
    bin = bdiff.bdiff(a, b)
    pos = 0
    while pos < len(bin):
        p1, p2, l = struct.unpack(">lll", bin[pos:pos + 12])
        pos += 12
        print p1, p2, repr(bin[pos:pos + l])
        pos += l
showdiff("x\n\nx\n\nx\n\nx\n\nz\n", "x\n\nx\n\ny\n\nx\n\nx\n\nz\n")
showdiff("x\n\nx\n\nx\n\nx\n\nz\n", "x\n\nx\n\ny\n\nx\n\ny\n\nx\n\nz\n")

print "done"

def testfixws(a, b, allws):
    c = bdiff.fixws(a, allws)
    if c != b:
        print "*** fixws", repr(a), repr(b), allws
        print "got:"
        print repr(c)

testfixws(" \ta\r b\t\n", "ab\n", 1)
testfixws(" \ta\r b\t\n", " a b\n", 0)
testfixws("", "", 1)
testfixws("", "", 0)

print "done"