[bug-patch] patch-2.5.9 - patch.c:340: main: Assertion `hunk' failed.

[Alexander Lamaison]

While transforming the patch code into a reusable library, I came
across a bug that is also present in the mainstream patch code.

When given an input appears to be a standard diff but has inconsistent
indentation (attached as test_data), intuit_diff_type() returns
NORMAL_DIFF as the type and sets the second line's indentation as the
indent for the whole file.  there_is_another_patch()  continues to
process the file but fails to find any hunks, presumably, because it
gets confused by the indentation.  Eventually this causes the
following assertion:

$ ./patch --dry-run < test_input
can't find file to patch at input line 1
Perhaps you should have used the -p or --strip option?
File to patch: patch
patching file patch
patch: patch.c:340: main: Assertion `hunk' failed.
Aborted

I've attached a patch that forces intuit_diff_type() to return NO_DIFF
when it finds that the indentation is inconsistent between the first
two lines of a standard diff.  I'm sure that there is a more graceful
way to handle this situation but I don't yet understand enough of the
code to find it.  My priority in making a library was to prevent any
code path that could lead to termination.

patch 2.5.9
gcc 4.2.4
Ubuntu Linux 8.04 Hardy Heron
x64

Hope this helps.

Alex Lamaison
--
http://www.doc.ic.ac.uk/~awl03

test_input
Description: Binary data

inconsistent_indent.patch
Description: Text Data