PHP_ADD_LIBRARY

I got strange results when configuring php with cpdf, dba, gd and jpeg/tiff. The problem was that cpdf requires jpeg and tiff libraries but did not check for them. Only in gd there were tests and missleeding hints: GD messages suggest that tiff/jpeg are only used there. As of current implementation both libs were added by calls to function PHP_ADD_LIBRARY in ext/cpdf/config.m4. Then in dba config tests failed because those two libs were missing. The above is fixed now in HEAD but there are other places where libraries are added with PHP_ADD_LIBRARY and without further checks. Also some libraries are linked more than once. Should we change PHP_ADD_LIBRARY and PHP_ADD_LIBRARY_WITH_PATH to check whether the library was already added and whether at least the file exists? marcus