BUG: don't append to ZLIB_NAMES

ENH: also check for zdll on windows
ENH: honor REQUIRED and QUIETLY

Alex

Modules/FindZLIB.cmake

@@ -5,23 +5,41 @@
 #  ZLIB_LIBRARIES   - List of libraries when using zlib.
 #  ZLIB_FOUND       - True if zlib found.
 
+
+IF (ZLIB_INCLUDE_DIR)
+  # Already in cache, be silent
+  SET(ZLIB_FIND_QUIETLY TRUE)
+ENDIF (ZLIB_INCLUDE_DIR)
+
 FIND_PATH(ZLIB_INCLUDE_DIR zlib.h
   /usr/local/include
   /usr/include
 )
 
-SET(ZLIB_NAMES ${ZLIB_NAMES} z zlib)
-FIND_LIBRARY(ZLIB_LIBRARY
-  NAMES ${ZLIB_NAMES}
-  PATHS /usr/lib /usr/local/lib
+SET(ZLIB_NAMES z zlib zdll)
+FIND_LIBRARY(ZLIB_LIBRARY 
+   NAMES ${ZLIB_NAMES}
+   PATHS /usr/lib /usr/local/lib
 )
 
-IF(ZLIB_INCLUDE_DIR)
-  IF(ZLIB_LIBRARY)
-    SET( ZLIB_LIBRARIES ${ZLIB_LIBRARY} )
-    SET( ZLIB_FOUND "YES" )
-  ENDIF(ZLIB_LIBRARY)
-ENDIF(ZLIB_INCLUDE_DIR)
+IF (ZLIB_INCLUDE_DIR AND ZLIB_LIBRARY)
+   SET(ZLIB_FOUND TRUE)
+   SET( ZLIB_LIBRARIES ${ZLIB_LIBRARY} )
+ELSE (ZLIB_INCLUDE_DIR AND ZLIB_LIBRARY)
+   SET(ZLIB_FOUND FALSE)
+   SET( ZLIB_LIBRARIES )
+ENDIF (ZLIB_INCLUDE_DIR AND ZLIB_LIBRARY)
+
+IF (ZLIB_FOUND)
+   IF (NOT ZLIB_FIND_QUIETLY)
+      MESSAGE(STATUS "Found ZLIB: ${ZLIB_LIBRARY}")
+   ENDIF (NOT ZLIB_FIND_QUIETLY)
+ELSE (ZLIB_FOUND)
+   IF (ZLIB_FIND_REQUIRED)
+      MESSAGE(STATUS "Looked for Z libraries named ${ZLIBS_NAMES}.")
+      MESSAGE(FATAL_ERROR "Could NOT find z library")
+   ENDIF (ZLIB_FIND_REQUIRED)
+ENDIF (ZLIB_FOUND)
 
 MARK_AS_ADVANCED(
   ZLIB_LIBRARY