I have noticed a strange problem with my Google maps v3 application: I
have an application containing a map with a WMS overlay, and a search
field which presents the user with up to five search hits at a time.
The WMS layer is implemented as an ImageMapType where I've overridden
The getTileUrl() method of the OverlayOptions object. Search results
are represented with markers in the map, and I use the extend method
on a LatLngBounds object to find the appropriate map bounds for
showing all the hits. Then I use the fitBounds(myExtendedBounds)
method on the map object to set the new bounds. This should sound like
a pretty standard use case?

My issue started when I noticed that my WMS tile server crashed during
the following scenario: First I zoomed down to an arbitrary town in
UK, and then tried to perform a search for something that gave
multiple search hits all over UK (Thereby expanding the map bounds
alot, in order to show all search results in the map).

What I found was that when the extendBounds/fitBounds methods were
fired, the client requested several extra tiles from my WMS server
with a strange bounding box. The reason that it crashed was that one
of my coordinate converter methods did not handle a bounding box
starting on the south pole (latitude = -90 degrees, made me end up
with log(0) in one of the formulas). I know the algorithm should
handle it properly, but the real question is:

Why does Google request overlays for map tiles with latitude = -90
degrees when I just navigate the map within UK?

PS: All the 16 overlay tiles that was supposed to be loaded, are
loaded OK. The strange south pole tiles are loaded in addition
(representing about 5 extra tiles). No extra tiles are requested for
the actual map, only the overlay.

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