ar fails when double-slashes are used in certain paths

[Nonconventionally Creative]

Binary package hint: binutils

Ubuntu Jaunty, binutils 2.19.1-0ubuntu3
Ubuntu Karmic, binutils 2.20-0ubuntu2
Expected: paths with double slashes work transparently, as in (most) other programs, or at the worst, give a relevant error message.
Actual: paths with double slashes fail silently (i.e. are not included in the archive) or with a bogus error message ("No such file" when it exists).
See attached script for test cases.

[Oliver Grawert (ogra)]

the same happens for paths with plus signs ...

(echo create /build/buildd/uboot-imx-2009.08+really2009.01/build/build-imx51/post/libpost.a; for lib in ; \
  do echo addlib $lib; done; echo save) \
 | ar -M
+Syntax error in archive script, line 1

[Loïc Minier (lool)]

This is specific to thin archives.

[Loïc Minier (lool)]

The test case mentions multiple problems, but I think it boils down to one: when the path to the archive to create has "//" and relative path names are used for files to put in the archive, the relative path stored in the archive is wrong (one "../" too much).

[Matthias Klose (doko)]

can't reproduce this in 14.10