Make hostile monsters with launcher and ammo keep away

If a hostile monster is wielding a ranged weapon, and is carrying
appropriate ammo for it, make the monster try to stay away,
outside the melee range.

doc/fixes37.0

@@ -133,6 +133,7 @@ male hero poly'd into nymph chooses charm vs seduce message based on being
 	male rather than on all nymphs being female but charm message was
 	using hardcoded pronouns She,her for target monster--wrong for male
 	target and noticable if "<mon> finishes taking off his suit" is given
+hostile monsters with launcher and ammo try to stay away from melee range
 
 
 Fixes to 3.7.0-x Problems that Were Exposed Via git Repository

include/extern.h

@@ -1660,6 +1660,7 @@ E void FDECL(Delay, (int));
 
 /* ### mthrowu.c ### */
 
+E boolean FDECL(m_has_launcher_and_ammo, (struct monst *));
 E int FDECL(thitu, (int, int, struct obj **, const char *));
 E int FDECL(ohitmon, (struct monst *, struct obj *, int, BOOLEAN_P));
 E void FDECL(thrwmu, (struct monst *));

src/monmove.c

@@ -999,6 +999,12 @@ register int after;
                     > ((ygold = findgold(g.invent)) ? ygold->quan : 0L))))
             appr = -1;
 
+        /* hostile monsters with ranged thrown weapons try to stay away */
+        if (!mtmp->mpeaceful
+            && (dist2(mtmp->mx, mtmp->my, mtmp->mux, mtmp->muy) < 5*5)
+            && m_canseeu(mtmp) && m_has_launcher_and_ammo(mtmp))
+            appr = -1;
+
         if (!should_see && can_track(ptr)) {
             register coord *cp;
 

src/mthrowu.c

@@ -26,6 +26,22 @@ static NEARDATA const char *breathwep[] = {
     "strange breath #9"
 };
 
+boolean
+m_has_launcher_and_ammo(mtmp)
+struct monst *mtmp;
+{
+    struct obj *mwep = MON_WEP(mtmp);
+
+    if (mwep && is_launcher(mwep)) {
+        struct obj *otmp;
+
+        for (otmp = mtmp->minvent; otmp; otmp = otmp->nobj)
+            if (ammo_and_launcher(otmp, mwep))
+                return TRUE;
+    }
+    return FALSE;
+}
+
 /* hero is hit by something other than a monster */
 int
 thitu(tlev, dam, objp, name)