Pets avoid a possible boulder pushing location in Sokoban

src/dogmove.c

@@ -1148,6 +1148,8 @@ dog_move(
         /* avoid a location hero just kicked */
         if (m_avoid_kicked_loc(mtmp, nx, ny))
             continue;
+        if (m_avoid_soko_push_loc(mtmp, nx, ny))
+            continue;
 
         {
             /* Dog avoids harmful traps, but perhaps it has to pass one

src/monmove.c

@@ -1240,6 +1240,21 @@ m_avoid_kicked_loc(struct monst *mtmp, coordxy nx, coordxy ny)
     return FALSE;
 }
 
+/* monster avoids a location nx, ny, if we're in sokoban, and
+   there's a boulder between the location and hero */
+boolean
+m_avoid_soko_push_loc(struct monst *mtmp, coordxy nx, coordxy ny)
+{
+    if (Sokoban
+        && (mtmp->mpeaceful || mtmp->mtame)
+        && !mtmp->mconf && !mtmp->mstun
+        && !Conflict
+        && (dist2(nx, ny, u.ux, u.uy) == 4)
+        && sobj_at(BOULDER, nx + sgn(u.ux - nx), ny + sgn(u.uy - ny)))
+        return TRUE;
+    return FALSE;
+}
+
 /* max distmin() distance for monster to look for items */
 #define SQSRCHRADIUS 5