Backported from X.Org:

commit 0801afbd7c2c644c672b37f8463f1a0cbadebd2e
Author: Erkki Seppälä <erkki.seppala@vincit.fi>
Date:   Thu Feb 10 15:35:14 2011 +0200

    record: avoid crash when calling RecordFlushReplyBuffer recursively

    RecordFlushReplyBuffer can call itself recursively through
    WriteClient->CallCallbacks->_CallCallbacks->RecordFlushAllContexts
    when the recording client's buffer cannot be completely emptied in one
    WriteClient. When a such a recursion occurs, it will not be broken out
    of which results in segmentation fault when the stack is exhausted.

    This patch adds a counter (a flag, really) that guards against this
    situation, to break out of the recursion.

    One alternative to this change would be to change _CallCallbacks to
    check the corresponding counter before the callback loop, but that
    might affect existing behavior, which may be relied upon.
Reviewed-by: Rami Ylimäki <rami.ylimaki@vincit.fi>
Signed-off-by: Erkki Seppälä <erkki.seppala@vincit.fi>
Signed-off-by: Keith Packard <keithp@keithp.com>
Backported-to-NX-by: Mihai Moldovan <ionic@ionic.de>

Fixes: ArcticaProject/nx-libs#417.