[SVN-2661] Should read hook output before reaping.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 1.1.x
• Fix Version/s: ---
• Component/s: libsvn_subr

Environment

Linux

• Assignee: Unassigned
• Reporter: Subversion Importer
• Created: 20/Nov/06 19:00
• Updated: 27/Oct/18 16:36
• Resolved: 20/Nov/06 19:28

Description

In svn_io_run_cmd (which is used to execute hooks), subversion calls waitpid()
on the child and only then reads the child's output. This means that if the
script attempts to create more output than will fit in the kernel buffer, a
deadlock condition will result -- the script waits for subversion to read, and
subversion waits for the script to exit.

The best way to handle this is to first read the script's standard error until
the read yields EOF (or EPIPE) and only then reap the child.

Original issue reported by zmandan

Issue Links

• duplicates: SVN-2078 Hook scripts hang if writing a lot to stderr