fix: refuse to open overly long URLs

ShellExecute on Wine can crash if you feed it a too long URL and
some browsers have been documented to have a fairly low max limit of
2083 characters.

This rejects URLs that are longer than 2048 characters.

Author: zao

engine/system/win/sys_main.cpp

@@ -412,7 +412,11 @@ void sys_main_c::SpawnProcess(const char* cmdName, const char* argList)
 void PlatformOpenURL(const char* url)
 {
 #ifdef _WIN32
-	ShellExecuteA(NULL, "open", url, NULL, NULL, SW_SHOWDEFAULT);
+	// There is a surprisingly low limit for the maximum URL length that ShellExecute and browsers can open.
+	// A common lower limit is 2083, so we'll refuse to open URLs smaller than this.
+	// Wine crashes violently if this is violated, 2k should be a safe enough limit while still allowing rather long links.
+	if (strlen(url) < 2048)
+		ShellExecuteA(NULL, "open", url, NULL, NULL, SW_SHOWDEFAULT);
 #else
 #warning LV: URL opening not implemented on this OS.
 	// TODO(LV): Implement URL opening for other OSes.