Merged revisions 69944 via svnmerge from

Merged revisions 69944 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4

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r69944 | russell | 2007-06-19 10:22:36 -0500 (Tue, 19 Jun 2007) | 10 lines

Fix a crash that could occur when handing device state changes.
When the state of a device changes, the device state thread tells the extension
state handling code that it changed.  Then, the extension state code calls the
callback in chan_sip so that it can update subscriptions to that extension.
A pointer to a sip_pvt structure is passed to this function as the call which
needs a NOTIFY sent.  However, there was no locking done to ensure that the pvt
struct didn't disappear during this process.
(issue #9946, reported by tdonahue, patch by me, patch updated to trunk to use
 the sip_pvt lock wrappers by eliel)

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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@69945 65c4cc65-6c06-0410-ace0-fbb531ad65f3