github issue #1472 - elven monster bow bonus

Issue reported by Tomsod: monster elves were intended to get a small
bonus to to-hit and damage when shooting arrows with bows, but the
check for that tested the arrows for skill P_BOW which never matches.
It should be -P_BOW.

[Pretty minor: +1 to-hit for any bow, another +1 to-hit if elven bow;
+1 damage for elven arrow; against hero and against other monsters.]

Fixes #1472

doc/fixes3-7-0.txt

@@ -1555,6 +1555,8 @@ dumplogs include spells and skills
 praying will not restore monster-form HP while polymorphed, unless you
         have unchanging
 winter wolf cub was missing for monster to lycanthrope conversion
+monster elves shooting arrows weren't getting intended small to-hit and damage
+	bonuses
 
 
 Fixes to 3.7.0-x General Problems Exposed Via git Repository

src/mthrowu.c

@@ -698,8 +698,9 @@ m_throw(
                     hitv = 3 - distmin(u.ux, u.uy, mon->mx, mon->my);
                     if (hitv < -4)
                         hitv = -4;
+                    /* [elves get a shooting bonus, orcs don't...] */
                     if (is_elf(mon->data)
-                        && objects[singleobj->otyp].oc_skill == P_BOW) {
+                        && objects[singleobj->otyp].oc_skill == -P_BOW) {
                         hitv++;
                         if (MON_WEP(mon) && MON_WEP(mon)->otyp == ELVEN_BOW)
                             hitv++;