fix test-mq-eol under --pure (mimic diffhelper.c behaviour)

bug discovered by apycot (apycot.hg-scm.org)

mercurial/pure/diffhelpers.py

@@ -1,56 +1,60 b''
 # diffhelpers.py - pure Python implementation of diffhelpers.c
 #
 # Copyright 2009 Matt Mackall <[e-mail]> and others
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 def addlines(fp, hunk, lena, lenb, a, b):
     while True:
         todoa = lena - len(a)
         todob = lenb - len(b)
         num = max(todoa, todob)
         if num == 0:
             break
         for i in xrange(num):
             s = fp.readline()
             c = s[0]
             if s == "\\ No newline at end of file\n":
                 fix_newline(hunk, a, b)
                 continue
             if c == "\n":
                 # Some patches may be missing the control char
                 # on empty lines. Supply a leading space.
                 s = " \n"
             hunk.append(s)
             if c == "+":
                 b.append(s[1:])
             elif c == "-":
                 a.append(s)
             else:
                 b.append(s[1:])
                 a.append(s)
     return 0
 
 def fix_newline(hunk, a, b):
     l = hunk[-1]
-    c = l[0]
+    # tolerate CRLF in last line
+    if l.endswith('\r\n'):
+        hline = l[:-2]
+    else:
     hline = l[:-1]
+    c = hline[0]
 
     if c == " " or c == "+":
-        b[-1] = l[1:-1]
+        b[-1] = hline[1:]
     if c == " " or c == "-":
         a[-1] = hline
     hunk[-1] = hline
     return 0
 
 
 def testhunk(a, b, bstart):
     alen = len(a)
     blen = len(b)
     if alen > blen - bstart:
         return -1
     for i in xrange(alen):
         if a[i][1:] != b[i + bstart]:
             return -1
     return 0