quake2.exe wrapper

Apparently something (possibly nvidia's driver) on some windows
installations has some stupid application profile for quake2.exe that
breaks mouse input if the console has been opened..

Our workaround is to rename quake2.exe to yquake2.exe and provide a wrapper
quake2.exe that just calls the real one for backwards compatibility.
This is the source of that wrapper.

src/win-wrapper/wrapper.c

@@ -0,0 +1,95 @@
+/*
+ * Just a trivial stupid wrapper quake2.exe that starts yquake2.exe.
+ * It calls it with the whole path (assuming it's in same directory as this wrapper)
+ * and passes the commandline
+ *
+ * This should allow us to rename the real executable to yquake2.exe (to hopefully
+ * avoid trouble with whatever stupid thing interferes with mouse input once
+ * console has been opened if the games executable is called quake2.exe)
+ * while avoiding confusion for people upgrading their yq2 installation who still have
+ * shortcuts (possibly in Steam) to quake2.exe that would otherwise launch an old version.
+ *
+ * Can be built with just
+ *   $ gcc -Wall -o quake2.exe wrapper.c
+ * in our mingw build environment, will only depend on kernel32.dll and MSVCRT.DLL then,
+ * which should be available on every Windows installation.
+ * 
+ * (C) 2017 Daniel Gibson
+ * License:
+ *  This software is dual-licensed to the public domain and under the following
+ *  license: you are granted a perpetual, irrevocable license to copy, modify,
+ *  publish, and distribute this file as you see fit.
+ *  No warranty implied; use at your own risk.
+ *
+ * So you can do whatever you want with this code, including copying it
+ * (or parts of it) into your own source.
+ */
+
+#include <windows.h>
+#include <wchar.h>
+#include <stdio.h>
+
+static const WCHAR WRAPPED_EXE[] = L"yquake2.exe";
+
+int main(int argc, char** argv)
+{
+	WCHAR* cmdLine = GetCommandLineW();
+	WCHAR exePath[2048];
+	WCHAR* lastBackSlash = exePath;
+	int maxLenSafe = sizeof(exePath)/sizeof(WCHAR) - wcslen(WRAPPED_EXE);
+
+	// get full path to this executable..
+	DWORD len = GetModuleFileNameW(NULL, exePath, maxLenSafe);
+	if(len <= 0 || len == maxLenSafe) {
+		// an error occured, clear exe path
+		exePath[0] = 0;
+	} else {
+		// .. cut off executable name (after last backslash in path)
+		lastBackSlash = wcsrchr(exePath, L'\\');
+		if(lastBackSlash != NULL) {
+			lastBackSlash[1] = 0;
+		} else {
+			// if there was no backslash, fall back to using only the wrapped exe name
+			// (appended to empty exePath buffer)
+			lastBackSlash = exePath;
+			lastBackSlash[0] = 0;
+		}
+	}
+
+	// .. append wrapped executable name to path ..
+	// should be safe, because maxLenSafe subtracted WRAPPED_EXE's length
+	// (and that's very conservative, we removed the original .exe name after all)
+	wcscat(lastBackSlash, WRAPPED_EXE);
+
+	// .. and start the wrapped executable
+	{
+		STARTUPINFOW si = {0};
+		PROCESS_INFORMATION pi = {0};
+		BOOL ret = FALSE;
+		si.cb = sizeof(si);
+
+		ret = CreateProcessW(exePath, cmdLine,
+		                     NULL,  // process security attributes
+		                     NULL,  // thread security attributes
+		                     FALSE, // don't inherit handles
+		                     0,     // no creation flag
+		                     NULL,  // environment block - no changes, use ours
+		                     NULL,  // don't change CWD
+		                     &si, &pi);
+
+		if(!ret)
+		{
+			fprintf(stderr, "Couldn't CreateProcess() (%ld).\n", GetLastError());
+			return 1;
+		}
+
+		// wait for wrapped exe to exit
+		WaitForSingleObject(pi.hProcess, INFINITE);
+
+		// close the process and thread object handles
+		CloseHandle(pi.hProcess);
+		CloseHandle(pi.hThread);
+	}
+
+	return 0;
+}