libiconv: add "enableShared" option

When false, shared libraries will be disabled.

also adds patch to *really* disable shared libiconv.

pkgs/development/libraries/libiconv/default.nix

@@ -1,6 +1,7 @@
 { fetchurl, stdenv, lib
 , buildPlatform, hostPlatform
 , enableStatic ? stdenv.hostPlatform.useAndroidPrebuilt
+, enableShared ? !stdenv.hostPlatform.useAndroidPrebuilt
 }:
 
 # assert !stdenv.isLinux || hostPlatform != buildPlatform; # TODO: improve on cross
@@ -23,10 +24,14 @@ stdenv.mkDerivation rec {
     lib.optionalString ((hostPlatform != buildPlatform && hostPlatform.libc == "msvcrt") || stdenv.cc.nativeLibc)
       ''
         sed '/^_GL_WARN_ON_USE (gets/d' -i srclib/stdio.in.h
-      '';
+      ''
+    + lib.optionalString (!enableShared) ''
+      sed -i -e '/preload/d' Makefile.in
+    '';
 
   configureFlags = lib.optional stdenv.isFreeBSD "--with-pic"
-    ++ lib.optional enableStatic "--enable-static";
+    ++ lib.optional enableStatic "--enable-static"
+    ++ lib.optional (!enableShared) "--disable-shared";
 
   meta = {
     description = "An iconv(3) implementation";

pkgs/os-specific/darwin/apple-source-releases/libiconv/default.nix

@@ -1,15 +1,19 @@
-{ stdenv, appleDerivation, autoreconfHook, targetPlatform, enableStatic ? targetPlatform.isiOS }:
+{ stdenv, appleDerivation, lib, autoreconfHook, targetPlatform
+, enableStatic ? targetPlatform.isiOS
+, enableShared ? !targetPlatform.isiOS
+}:
 
 appleDerivation {
   postUnpack = "sourceRoot=$sourceRoot/libiconv";
 
-  preConfigure = stdenv.lib.optionalString stdenv.hostPlatform.isiOS ''
+  preConfigure = lib.optionalString stdenv.hostPlatform.isiOS ''
     sed -i 's/darwin\*/ios\*/g' configure libcharset/configure
   '';
 
-  configureFlags = stdenv.lib.optionals enableStatic [ "--enable-static" "--disable-shared" ];
+  configureFlags = lib.optional enableStatic "--enable-static"
+                ++ lib.optional (!enableShared) "--disable-shared";
 
-  postInstall = stdenv.lib.optionalString (!enableStatic) ''
+  postInstall = lib.optionalString (!enableStatic) ''
     mv $out/lib/libiconv.dylib $out/lib/libiconv-nocharset.dylib
     ${stdenv.cc.bintools.targetPrefix}install_name_tool -id $out/lib/libiconv-nocharset.dylib $out/lib/libiconv-nocharset.dylib
 
@@ -26,6 +30,6 @@ appleDerivation {
   ];
 
   meta = {
-    platforms = stdenv.lib.platforms.darwin;
+    platforms = lib.platforms.darwin;
   };
 }