Try having relative paths in pkg-config file.

Addresses #248

Author: 0-wiz-0

CMakeLists.txt

@@ -281,11 +281,12 @@ endif()
 
 
 # pkgconfig file
-set(prefix ${CMAKE_INSTALL_PREFIX})
-set(exec_prefix \${prefix})
-SET(bindir ${CMAKE_INSTALL_FULL_BINDIR})
-SET(libdir ${CMAKE_INSTALL_FULL_LIBDIR})
-SET(includedir ${CMAKE_INSTALL_FULL_INCLUDEDIR})
+file(RELATIVE_PATH pc_relative_bindir ${CMAKE_INSTALL_PREFIX} ${CMAKE_INSTALL_FULL_BINDIR})
+set(bindir "\${prefix}/${pc_relative_bindir}")
+file(RELATIVE_PATH pc_relative_libdir ${CMAKE_INSTALL_PREFIX} ${CMAKE_INSTALL_FULL_LIBDIR})
+set(libdir "\${prefix)/${pc_relative_libdir}")
+file(RELATIVE_PATH pc_relative_includedir ${CMAKE_INSTALL_PREFIX} ${CMAKE_INSTALL_FULL_INCLUDEDIR})
+set(includedir "\${prefix}/${pc_relative_includedir}")
 if(CMAKE_SYSTEM_NAME MATCHES BSD)
   set(PKG_CONFIG_RPATH "-Wl,-R\${libdir}")
 endif(CMAKE_SYSTEM_NAME MATCHES BSD)

libzip.pc.in

@@ -1,15 +1,14 @@
-prefix=@prefix@
-exec_prefix=@exec_prefix@
+prefix=@CMAKE_INSTALL_PREFIX@
+exec_prefix=${prefix}
 bindir=@bindir@
 libdir=@libdir@
 includedir=@includedir@
 
-zipcmp=@bindir@/zipcmp
+zipcmp=${bindir}/zipcmp
 
 Name: libzip
 Description: library for handling zip archives
 Version: @PROJECT_VERSION@
 Libs: @PKG_CONFIG_RPATH@ -L${libdir} -lzip
 Libs.private: @LIBS@
 Cflags: -I${includedir}
-