+/*
+====================
+FS_CheckNastyPath
+
+Return true if the path should be rejected due to one of the following:
+1: path elements that are non-portable
+2: path elements that would allow access to files outside the game directory,
+ or are just not a good idea for a mod to be using.
+====================
+*/
+int FS_CheckNastyPath (const char *path)
+{
+ // Windows: don't allow \ in filenames (windows-only), period.
+ // (on Windows \ is a directory separator, but / is also supported)
+ if (strstr(path, "\\"))
+ return 1; // non-portable
+ // Mac: don't allow Mac-only filenames - : is a directory separator
+ // instead of /, but we rely on / working already, so there's no reason to
+ // support a Mac-only path
+ // Amiga and Windows: : tries to go to root of drive
+ if (strstr(path, ":"))
+ return 1; // non-portable attempt to go to root of drive
+ // Amiga: // is parent directory
+ if (strstr(path, "//"))
+ return 1; // non-portable attempt to go to parent directory
+ // all: don't allow going to current directory (./) or parent directory (../ or /../)
+ if (strstr(path, "./"))
+ return 2; // attempt to go to parent directory
+ // after all these checks we're pretty sure it's a / separated filename
+ // and won't do much if any harm
+ return false;
+}
+