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from subprocess import Popen, PIPE
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Diff and patch functionality
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__docformat__ = "restructuredtext"
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def write_to_cmd(args, input=""):
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process = Popen(args, bufsize=len(input), stdin=PIPE, stdout=PIPE,
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stderr=PIPE, close_fds=True)
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stdout, stderr = process.communicate(input)
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status = process.wait()
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raise Exception("%s killed by signal %i" (args[0], -status))
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return stdout, stderr, status
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def patch(patch_contents, filename, output_filename=None, reverse=False):
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"""Apply a patch to a file, to produce another output file. This is should
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be suitable for our limited purposes.
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:param patch_contents: The contents of the patch to apply
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:type patch_contents: str
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:param filename: the name of the file to apply the patch to
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:param output_filename: The filename to produce. If None, file is \
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:type output_filename: str or NoneType
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:param reverse: If true, apply the patch in reverse
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:return: 0 on success, 1 if some hunks failed
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args = ["patch", "-f", "-s", "--posix", "--binary"]
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args.append("--reverse")
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if output_filename is not None:
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args.extend(("-o", output_filename))
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stdout, stderr, status = write_to_cmd(args, patch_contents)
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def diff(orig_file, mod_str, orig_label=None, mod_label=None):
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"""Compare two files, and produce a patch.
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:param orig_file: path to the old file
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:param mod_str: Contents of the new file
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:param orig_label: The label to use for the old file
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:param mod_label: The label to use for the new file
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args = ["diff", "-u" ]
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if orig_label is not None and mod_label is not None:
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args.extend(("-L", orig_label, "-L", mod_label))
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args.extend(("--", orig_file, "-"))
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patch, stderr, status = write_to_cmd(args, mod_str)
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def diff3(out_file, mine_path, older_path, yours_path):
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def add_label(args, label):
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args.extend(("-L", label))
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args = ['diff3', "-E", "--merge"]
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add_label(args, "TREE")
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add_label(args, "ANCESTOR")
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add_label(args, "MERGE-SOURCE")
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args.extend((mine_path, older_path, yours_path))
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output, stderr, status = write_to_cmd(args)
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if status not in (0, 1):
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raise Exception(stderr)
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file(out_file, "wb").write(output)