#!/bin/sh
#
# Convert CVS's diff format to patch's.
#
# This program acts like a unix filter: send it a
# CVS patch on stdin and it'll print a patch-compatible
# patch on stdout.
#
# You *must* use the -u option to "cvs diff"!

grep -v "^cvs diff: " | # no need to pass '-q'
  awk '
    /^Index: / {
      file = $2
    }

    /^diff -u -r/ {
      a = $3;
      b = $4;
      if (b !~ /^-r/) b = "HEAD"
      $0 = "diff --cvsish " a "/" file " " b "/" file
    }

    /^--- / {
      $2 = a "/" $2
    }

    /^\+\+\+ / {
      $2 = b "/" $2
    }

    { print }
'

exit

# Some sample diff headers:

Index: foo.txt
===================================================================
RCS file: /cvs/foo.txt,v
retrieving revision 1.6
retrieving revision 1.5
diff -u -r1.6 -r1.5
--- foo.txt     29 Dec 2008 21:12:45 -0000      1.6
+++ foo.txt     27 Aug 2008 20:05:37 -0000      1.5
@@ -45,19 +45,20 @@


Index: bar.txt
===================================================================
RCS file: /cvs/bar.txt,v
retrieving revision 1.22
diff -u -r1.22 bar.txt
--- bar.txt        8 Nov 2008 19:59:03 -0000       1.22
+++ bar.txt        16 Jan 2009 21:38:21 -0000
@@ -42,7 +42,6 @@