Created attachment 144335 [details]
Sample address books and backtrace log

I am trying to merge two address books, which between them contain more than
one instance of the same person, so Evolution comes up with a merge dialog.

Most of the time, merging just works. However, if the contacts in question have
different numbers of email addresses (e.g., one contact has two email addresses
and the other has none), when I click the Merge button, the CPU shoots up to
100% and Evolution stops responding. Even the Merge button keeps its "pressed
in" appearance, while the background Evolution window darkens (as is typical
for an unresponsive window in Ubuntu, which I'm currently running).

For your convenience, I've attached the following:

 * test01.tar.bz2 and test02.tar.bz2. These are sample address books which
illustrate the problem; each contains one dummy record. Direction of merge is
from test01 to test02. Interestingly enough, the problem does not happen in the
reverse direction with these particular records.

 * Backtraces produced using gdb on separate runs. One for evolution itself;
the other for the evolution-data-server.