[krbdev.mit.edu #8707] git commit

[Greg Hudson via RT]

Improve ulog memory hygiene

Add a helper create_log_context() to initialize a krb5_context's
kdblog_context field, setting ulogfd to -1.  Use it in ulog_set_role()
and ulog_map().  In ulog_fini(), release ulogfd if it is not -1.

In ulog_map(), add a cleanup label and use it to finalize the log
context on failure, so that we don't (trivially) leak the mapped ulog.
To reduce the number of "retval = errno;" statements required for this
change, make extend_file_to() return a krb5_error_code.

The ulog leak on error was reported by Bean Zhang.

https://github.com/krb5/krb5/commit/7aff2511c0dab5c51b1155ca2952521ffb925fc5
Author: Greg Hudson <ghudson at mit.edu>
Commit: 7aff2511c0dab5c51b1155ca2952521ffb925fc5
Branch: master
 src/lib/kdb/kdb_log.c |  125 +++++++++++++++++++++++++-----------------------
 src/slave/kproplog.c  |    4 +-
 2 files changed, 68 insertions(+), 61 deletions(-)