[Fix] Another possible segfault with isspace().

src/intro.c

@@ -13,6 +13,7 @@
 #include "ldata.h"
 #include "font.h"
 #include "music.h"
+#include "lstd.h"
 #include "intro.h"
 
 #define INTRO_FONT_SIZE 18. /**< Intro text font size. */
@@ -129,7 +130,8 @@ int intro_display(void) {
           /* Skip the boring intro we saw a million times already! */
           if(event.key.keysym.sym == SDLK_ESCAPE)
             offset = max * (intro_font.h + 5.);
-          else if(!isspace(event.key.keysym.sym))
+          /* Only handle space from here down. */
+          else if(!lstd_isspace(event.key.keysym.sym))
             break;
         /* Purpose fallthrough. */
         case SDL_JOYBUTTONDOWN:

src/lstd.h

@@ -21,3 +21,8 @@
  */
 #define lstd_iscntrl(k) (lstd_checkascii(k) ? iscntrl(k) : 0)
 
+/**
+ * @brief Check to see if a key is a space character.
+ */
+#define lstd_isspace(k) (lstd_checkascii(k) ? isspace(k) : 0)
+