[wp-trac] [WordPress Trac] #31767: insert_with_markers() is not atomic, leading to corrupted .htaccess updates under race conditions

[WordPress Trac]

#31767: insert_with_markers() is not atomic, leading to corrupted .htaccess updates
under race conditions
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 Reporter:  tigertech            |       Owner:  dd32
     Type:  defect (bug)         |      Status:  assigned
 Priority:  normal               |   Milestone:  4.4
Component:  Filesystem API       |     Version:  4.1.1
 Severity:  critical             |  Resolution:
 Keywords:  has-patch 4.4-early  |     Focuses:
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Comment (by dd32):

 [34740] is my attempt at handling this using `flock()`.

 So far in testing, I'm able to consistently duplicate file corruption
 before the patch, and also when locking isn't available.
 Unfortunately we can't use a second temporary file in a lot of cases, so I
 decided against using an atomic file move.

 Leaving this open to see if there's any other suggestions we could go
 down, or if any bugs crop up (please test)

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Ticket URL: <https://core.trac.wordpress.org/ticket/31767#comment:16>
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