lock_acquire() fails miserably when a comma is used as decimal separator (through LC_ALL or LC_NUMERIC)

We were experiencing intermittent 50 second page load times and tracked it down to having changed decimal separator from "." to "," by setting LC_ALL to a european locale.

This was tracked down to lock.inc:116 - lock_acquire() using the following SQL query:

      if (@db_query("INSERT INTO {semaphore} (name, value, expire) VALUES ('%s', '%s', %f)", $name, _lock_id(), $expire)) {

Since the $expire was casted to (float) with a comma as decimal-separator, the resulting query sent to MySQL was:

INSERT INTO shared_semaphore (name, value, expire) VALUES ('variable_cache_regenerate', '6663815504ee21ea015d860.32870955', 1323441855,1033)

... this made the query fail, causing drupal error reporting to wake up, and in some stage variable_init() was re-triggered, causing a recursion that only stopped because of the recursion protection within variable_init() ("if ($recursion_depth < 50) {"). A timeout for 1 second on each lock resulted in the 50 second page load times.

Locally, we have this solved by changing lock.inc:116 simply to:

      if (@db_query("INSERT INTO {semaphore} (name, value, expire) VALUES ('%s', '%s', '%f')", $name, _lock_id(), $expire)) {

Hope this helps some poor european drupal user :)