ensure getUser() returns a valid player name

src/porting.cpp

@@ -33,6 +33,7 @@
 #include "config.h"
 #include "debug.h"
 #include "filesys.h"
+#include "player.h"
 
 #ifdef __APPLE__
 	#include "CoreFoundation/CoreFoundation.h"
@@ -374,19 +375,20 @@ void initializePaths(char* argv0)
 
 std::string getUser()
 {
+	std::string user("someone");
 #ifdef _WIN32
 
 	char buff[1024];
 	int size = 1024;
 
 	if (GetUserName(buff,LPDWORD(&size)))
-		return std::string(buff);
+		user = std::string(buff);
 #else
 	char* u = getenv("USER");
 	if (u)
-		return std::string(u);
+		user = std::string(u);
 #endif
-	return std::string("someone");
+	return string_allowify(user,PLAYERNAME_ALLOWED_CHARS);
 }
 
 } //namespace porting

src/utility.h

@@ -1413,23 +1413,34 @@ private:
 */
 inline bool string_allowed(const std::string &s, const std::string &allowed_chars)
 {
-	for(u32 i=0; i<s.size(); i++)
-	{
+	for (u32 i=0; i<s.size(); i++) {
 		bool confirmed = false;
-		for(u32 j=0; j<allowed_chars.size(); j++)
-		{
-			if(s[i] == allowed_chars[j])
-			{
+		for (u32 j=0; j<allowed_chars.size(); j++) {
+			if (s[i] == allowed_chars[j]) {
 				confirmed = true;
 				break;
 			}
 		}
-		if(confirmed == false)
+		if (confirmed == false)
 			return false;
 	}
 	return true;
 }
 
+inline std::string string_allowify(const std::string &s, const std::string &allowed_chars)
+{
+	std::string result;
+	for (u32 i=0; i<s.size(); i++) {
+		for (u32 j=0; j<allowed_chars.size(); j++) {
+			if (s[i] == allowed_chars[j]) {
+				result += s[i];
+				break;
+			}
+		}
+	}
+	return result;
+}
+
 /*
 	Some helper stuff
 */