The archiver options in the CMake file should disable, not enable.

We now try to compile all archivers by default unless one explicit disables
them individually, so these options needed to be handled differently.

CMakeLists.txt

@@ -221,57 +221,59 @@ endif()
 
 
 # Archivers ...
+# These are (mostly) on by default now, so these options are only useful for
+#  disabling them.
 
 option(PHYSFS_ARCHIVE_ZIP "Enable ZIP support" TRUE)
-if(PHYSFS_ARCHIVE_ZIP)
-    add_definitions(-DPHYSFS_SUPPORTS_ZIP=1)
+if(NOT PHYSFS_ARCHIVE_ZIP)
+    add_definitions(-DPHYSFS_SUPPORTS_ZIP=0)
 endif()
 
 option(PHYSFS_ARCHIVE_7Z "Enable 7zip support" TRUE)
-if(PHYSFS_ARCHIVE_7Z)
-    add_definitions(-DPHYSFS_SUPPORTS_7Z=1)
+if(NOT PHYSFS_ARCHIVE_7Z)
+    add_definitions(-DPHYSFS_SUPPORTS_7Z=0)
     # !!! FIXME: rename to 7z.c?
     set(PHYSFS_SRCS ${PHYSFS_SRCS} ${LZMA_SRCS})
 endif()
 
 option(PHYSFS_ARCHIVE_GRP "Enable Build Engine GRP support" TRUE)
-if(PHYSFS_ARCHIVE_GRP)
-    add_definitions(-DPHYSFS_SUPPORTS_GRP=1)
+if(NOT PHYSFS_ARCHIVE_GRP)
+    add_definitions(-DPHYSFS_SUPPORTS_GRP=0)
 endif()
 
 option(PHYSFS_ARCHIVE_WAD "Enable Doom WAD support" TRUE)
-if(PHYSFS_ARCHIVE_WAD)
-    add_definitions(-DPHYSFS_SUPPORTS_WAD=1)
+if(NOT PHYSFS_ARCHIVE_WAD)
+    add_definitions(-DPHYSFS_SUPPORTS_WAD=0)
 endif()
 
 option(PHYSFS_ARCHIVE_HOG "Enable Descent I/II HOG support" TRUE)
-if(PHYSFS_ARCHIVE_HOG)
-    add_definitions(-DPHYSFS_SUPPORTS_HOG=1)
+if(NOT PHYSFS_ARCHIVE_HOG)
+    add_definitions(-DPHYSFS_SUPPORTS_HOG=0)
 endif()
 
 option(PHYSFS_ARCHIVE_MVL "Enable Descent I/II MVL support" TRUE)
-if(PHYSFS_ARCHIVE_MVL)
-    add_definitions(-DPHYSFS_SUPPORTS_MVL=1)
+if(NOT PHYSFS_ARCHIVE_MVL)
+    add_definitions(-DPHYSFS_SUPPORTS_MVL=0)
 endif()
 
 option(PHYSFS_ARCHIVE_QPAK "Enable Quake I/II QPAK support" TRUE)
-if(PHYSFS_ARCHIVE_QPAK)
-    add_definitions(-DPHYSFS_SUPPORTS_QPAK=1)
+if(NOT PHYSFS_ARCHIVE_QPAK)
+    add_definitions(-DPHYSFS_SUPPORTS_QPAK=0)
 endif()
 
 option(PHYSFS_ARCHIVE_SLB "Enable I-War / Independence War SLB support" TRUE)
-if(PHYSFS_ARCHIVE_SLB)
-    add_definitions(-DPHYSFS_SUPPORTS_SLB=1)
+if(NOT PHYSFS_ARCHIVE_SLB)
+    add_definitions(-DPHYSFS_SUPPORTS_SLB=0)
 endif()
 
 option(PHYSFS_ARCHIVE_ISO9660 "Enable ISO9660 support" TRUE)
-if(PHYSFS_ARCHIVE_ISO9660)
-    add_definitions(-DPHYSFS_SUPPORTS_ISO9660=1)
+if(NOT PHYSFS_ARCHIVE_ISO9660)
+    add_definitions(-DPHYSFS_SUPPORTS_ISO9660=0)
 endif()
 
 option(PHYSFS_ARCHIVE_VDF "Enable Gothic I/II VDF archive support" TRUE)
-if(PHYSFS_ARCHIVE_VDF)
-    add_definitions(-DPHYSFS_SUPPORTS_VDF=1)
+if(NOT PHYSFS_ARCHIVE_VDF)
+    add_definitions(-DPHYSFS_SUPPORTS_VDF=0)
 endif()