Fix truncation of GetDebugString output string

See: #525

src/console_cmds.cpp

@@ -1774,7 +1774,7 @@ DEF_CONSOLE_CMD(ConDebugLevel)
 	if (argc > 2) return false;
 
 	if (argc == 1) {
-		IConsolePrintF(CC_DEFAULT, "Current debug-level: '%s'", GetDebugString());
+		IConsolePrintF(CC_DEFAULT, "Current debug-level: '%s'", GetDebugString().c_str());
 	} else {
 		SetDebugString(argv[1], [](const char *err) { IConsolePrint(CC_ERROR, err); });
 	}

src/debug.cpp

@@ -313,22 +313,13 @@ void SetDebugString(const char *s, void (*error_func)(const char *))
  * Just return a string with the values of all the debug categories.
  * @return string with debug-levels
  */
-const char *GetDebugString()
+std::string GetDebugString()
 {
-	const DebugLevel *i;
-	static char dbgstr[150];
-	char dbgval[20];
-
-	memset(dbgstr, 0, sizeof(dbgstr));
-	i = debug_level;
-	seprintf(dbgstr, lastof(dbgstr), "%s=%d", i->name, *i->level);
-
-	for (i++; i != endof(debug_level); i++) {
-		seprintf(dbgval, lastof(dbgval), ", %s=%d", i->name, *i->level);
-		strecat(dbgstr, dbgval, lastof(dbgstr));
+	std::string result;
+	for (size_t i = 0; i < lengthof(debug_level); i++) {
+		result += stdstr_fmt("%s%s=%d", i == 0 ? "" : ", ", debug_level[i].name, *(debug_level[i].level));
 	}
-
-	return dbgstr;
+	return result;
 }
 
 /**

src/debug.h

@@ -69,7 +69,7 @@ void debug_print(const char *dbg, const char *buf);
 
 char *DumpDebugFacilityNames(char *buf, char *last);
 void SetDebugString(const char *s, void (*error_func)(const char *));
-const char *GetDebugString();
+std::string GetDebugString();
 
 /* Shorter form for passing filename and linenumber */
 #define FILE_LINE __FILE__, __LINE__