fix issue #1337 - 'fireassist' vs 'f'iring aklys

Issue reported by elunna:  if the 'fireassist' option is on and the
quiver contains ammo, 'f' while wielding an aklys switches to the
ammo's launcher instead of throwing the aklys.

Fixes #1337

doc/fixes3-7-0.txt

@@ -2069,6 +2069,8 @@ non-fireproof water walking boots wouldn't be burnt up if fire resistant hero
 	at wall locations
 if a pile of objects had plain arrow(s) on top, map location classification
 	got confused and reported 'unexplored area'
+when the 'fireassist' option was on, 'f' would choose uquiver over wielded
+	throw-and-return uwep
 
 
 Fixes to 3.7.0-x Platform and/or Interface Problems Exposed Via git Repository

src/dothrow.c

@@ -472,7 +472,8 @@ dofire(void)
        on its caller to make sure hero is strong enough to throw that */
     boolean uwep_Throw_and_Return = (uwep && AutoReturn(uwep, uwep->owornmask)
                                      && (uwep->oartifact != ART_MJOLLNIR
-                                         || ACURR(A_STR) >= STR19(25)));
+                                         || ACURR(A_STR) >= STR19(25))),
+            skip_fireassist = FALSE;
     int altres, res = ECMD_OK;
 
     /*
@@ -502,6 +503,7 @@ dofire(void)
        throwing Mjollnir if quiver contains daggers] */
     if (uwep_Throw_and_Return && (!obj || is_ammo(obj))) {
         obj = uwep;
+        skip_fireassist = TRUE;
 
     } else if (!obj) {
         if (!flags.autoquiver) {
@@ -550,7 +552,8 @@ dofire(void)
         obj = uquiver;
     }
 
-    if (uquiver && is_ammo(uquiver) && iflags.fireassist) {
+    if (uquiver && is_ammo(uquiver) && iflags.fireassist
+        && !skip_fireassist) {
         struct obj *olauncher;
 
         if (uwep && is_pole(uwep) && could_pole_mon())