Unify impaired movement direction checks

src/apply.c

@@ -355,8 +355,7 @@ use_stethoscope(struct obj *obj)
         You_hear("your heart beat.");
         return res;
     }
-    if (Stunned || (Confusion && !rn2(5)))
-        confdir();
+    confdir(FALSE);
     if (!u.dx && !u.dy) {
         ustatusline();
         return res;
@@ -2850,8 +2849,7 @@ use_whip(struct obj *obj)
         rx = mtmp->mx;
         ry = mtmp->my;
     } else {
-        if (Stunned || (Confusion && !rn2(5)))
-            confdir();
+        confdir(FALSE);
         rx = u.ux + u.dx;
         ry = u.uy + u.dy;
         if (!isok(rx, ry)) {

src/cmd.c

@@ -4607,8 +4607,8 @@ getdir(const char *s)
         You_cant("orient yourself that direction.");
         return 0;
     }
-    if (!u.dz && (Stunned || (Confusion && !rn2(5))))
-        confdir();
+    if (!u.dz)
+        confdir(FALSE);
     return 1;
 }
 
@@ -4789,14 +4789,16 @@ help_dir(
     return TRUE;
 }
 
+/* if hero is impaired, pick random movement direction */
 void
-confdir(void)
+confdir(boolean force_impairment)
 {
-    register coordxy x = NODIAG(u.umonnum) ? dirs_ord[rn2(4)] : rn2(N_DIRS);
+    if (force_impairment || u_maybe_impaired()) {
+        register coordxy x = NODIAG(u.umonnum) ? dirs_ord[rn2(4)] : rn2(N_DIRS);
 
-    u.dx = xdir[x];
-    u.dy = ydir[x];
-    return;
+        u.dx = xdir[x];
+        u.dy = ydir[x];
+    }
 }
 
 const char *

src/dig.c

@@ -1058,8 +1058,7 @@ use_pick_axe2(struct obj *obj)
         g.context.botl = 1;
         return ECMD_TIME;
     } else if (u.dz == 0) {
-        if (Stunned || (Confusion && !rn2(5)))
-            confdir();
+        confdir(FALSE);
         rx = u.ux + u.dx;
         ry = u.uy + u.dy;
         if (!isok(rx, ry)) {

src/hack.c

@@ -2046,11 +2046,17 @@ slippery_ice_fumbling(void)
         HFumbling &= ~FROMOUTSIDE;
 }
 
+boolean
+u_maybe_impaired(void)
+{
+    return (Stunned || (Confusion && !rn2(5)));
+}
+
 /* change movement dir if impaired. return TRUE if can't move */
 static boolean
 impaired_movement(coordxy *x, coordxy *y)
 {
-    if (Stunned || (Confusion && !rn2(5))) {
+    if (u_maybe_impaired()) {
         register int tries = 0;
 
         do {
@@ -2058,7 +2064,7 @@ impaired_movement(coordxy *x, coordxy *y)
                 nomul(0);
                 return TRUE;
             }
-            confdir();
+            confdir(TRUE);
             *x = u.ux + u.dx;
             *y = u.uy + u.dy;
         } while (!isok(*x, *y) || bad_rock(g.youmonst.data, *x, *y));