Ivan Zhakov wrote: > On 10 December 2015 at 19:14, Julian Foad <julianf...@apache.org> wrote: >> APR devs, Subversion devs: >> >> On Subversion's Mac OS buildbots it appears that apr_hash_overlay() >> sometimes returns a hash containing duplicate keys, which (as I >> understand it) should be impossible. >> >> We had an issue where some 'svnmover' tests were failing only on Mac >> OS buildbots. I added some debugging in Subversion commits r1719056, >> r1719067, r1719072, r1719074. >> >> Buildbot result: >> >> https://ci.apache.org/builders/svn-x64-macosx-bdb/builds/485/steps/Test%20ra_svn%2Bbdb >> --> debug output in 'faillog' shows duplicate keys in hash: >> "union_children={A, iota, foo, boozle, boozle, iota}" >> >> I replaced apr_hash_overlay() with my own simple re-implementation: >> >> http://svn.apache.org/r1719089 -- re-implement hash overlay >> > Hi Julian, > > That could be possible if two hashes uses different hash functions. > This could happen if you're using svn_hash__make() directly or > indirectly: for example RA get_dirent for svn:// protocol returns hash > with non-standard hash-function.
Ugh. Yes, that is probably the cause. Thanks. I can see now that the doc string of apr_hash_overlay() does say "Both hash tables must use the same hash function" but that was not obvious, and I had totally forgotten that our Subversion code was using more than one hash function. I will use my own hash overlay function from now on. - Julian
