Attempt to make diff deal with null sources properly

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Hash: SHA1

Attempt to make diff deal with null sources properly

manifest hash: 7766ed2b885640157b93474b6e42573ec061fcfb
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Version: GnuPG v1.4.0 (GNU/Linux)

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mercurial/commands.py

@@ -61,12 +61,12 b' def dodiff(repo, files = None, node1 = N'
         tn = read(f)
         sys.stdout.write(mdiff.unidiff(to, date1, tn, date2, f))
     for f in a:
-        to = ""
+        to = None
         tn = read(f)
         sys.stdout.write(mdiff.unidiff(to, date1, tn, date2, f))
     for f in d:
         to = repo.file(f).read(mmap[f])
-        tn = ""
+        tn = None
         sys.stdout.write(mdiff.unidiff(to, date1, tn, date2, f))
     
 def help(ui, cmd=None):

mercurial/mdiff.py

@@ -10,6 +10,20 b' from mercurial.mpatch import *'
 
 def unidiff(a, ad, b, bd, fn):
     if not a and not b: return ""
+
+    if a == None:
+        b = b.splitlines(1)
+        l1 = "--- %s\t%s\n" % ("/dev/null", ad)
+        l2 = "+++ %s\t%s\n" % ("b/" + fn, bd)
+        l3 = "@@ -0,0 +1,%d @@\n" % len(b)
+        l = [l1, l2, l3] + ["+" + e for e in b]
+    elif b == None:
+        a = a.splitlines(1)
+        l1 = "--- %s\t%s\n" % ("a/" + fn, ad)
+        l2 = "+++ %s\t%s\n" % ("/dev/null", bd)
+        l3 = "@@ -1,%d +0,0 @@\n" % len(a)
+        l = [l1, l2, l3] + ["-" + e for e in a]
+    else:
     a = a.splitlines(1)
     b = b.splitlines(1)
     l = list(difflib.unified_diff(a, b, "a/" + fn, "b/" + fn, ad, bd))