Fix building for Android and add build instructions to README

README

@@ -81,6 +81,17 @@ LibVNCServer uses CMake, so you can build via:
 For some more comprehensive examples that include installation of dependencies, see
 the [Unix CI](.travis.yml) and [Windows CI](.appveyor.yml) build setups.
 
+Crosscompiling involves some more advanced command line switches but is easily possible
+as well.
+
+For instance, building for Android (see https://developer.android.com/ndk/guides/cmake.html as a reference):
+
+    mkdir build
+    cd build
+    cmake .. -DANDROID_NDK=<path> -DCMAKE_TOOLCHAIN_FILE=<path> -DANDROID_NATIVE_API_LEVEL=<API level you want> -DWITH_PNG=OFF # NDK not shipping png per default
+    cmake --build .
+
+
 How to use
 ----------
 

libvncclient/listen.c

@@ -89,7 +89,7 @@ listenForIncomingConnections(rfbClient* client)
     int r;
     /* reap any zombies */
     int status, pid;
-    while ((pid= wait3(&status, WNOHANG, (struct rusage *)0))>0);
+    while ((pid= wait4(-1, &status, WNOHANG, (struct rusage *)0))>0);
 
     /* TODO: callback for discard any events (like X11 events) */
 

rfb/rfbclient.h

@@ -35,6 +35,11 @@
 #define WIN32_LEAN_AND_MEAN /* Prevent loading any Winsock 1.x headers from windows.h */
 #endif
 
+#if defined(ANDROID) || defined(LIBVNCSERVER_HAVE_ANDROID)
+#include <arpa/inet.h>
+#include <sys/select.h>
+#endif
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>