more PR #771 - blast vs spell

Add the patch from entrez to describe the tower of flame effect from
a scroll of fire as "the blast" rather than "your spell" if it reveals
a secret door.

src/explode.c

@@ -85,6 +85,9 @@ explode(
     } else if (olet == BURNING_OIL) {
         /* used to provide extra information to zap_over_floor() */
         exploding_wand_typ = POT_OIL;
+    } else if (olet == SCROLL_CLASS) {
+        /* ditto */
+        exploding_wand_typ = SCR_FIRE;
     }
     /* muse_unslime: SCR_FIRE */
     if (expltype < 0) {

src/read.c

@@ -1763,7 +1763,9 @@ seffect_fire(struct obj **sobjp)
             burn_away_slime();
         }
     }
-    explode(cc.x, cc.y, 11, dam, SCROLL_CLASS, EXPL_FIERY);
+#define ZT_SPELL_O_FIRE 11 /* explained in splatter_burning_oil(explode.c) */
+    explode(cc.x, cc.y, ZT_SPELL_O_FIRE, dam, SCROLL_CLASS, EXPL_FIERY);
+#undef ZT_SPELL_O_FIRE
 }
 
 static void

src/zap.c

@@ -4841,11 +4841,13 @@ zap_over_floor(
             zapverb = "bolt"; /* wand zap */
         else if (abs(type) < ZT_BREATH(0))
             zapverb = "spell";
-    } else if (exploding_wand_typ == POT_OIL) {
+    } else if (exploding_wand_typ == POT_OIL
+               || exploding_wand_typ == SCR_FIRE) {
         /* breakobj() -> explode_oil() -> splatter_burning_oil()
            -> explode(ZT_SPELL(ZT_FIRE), BURNING_OIL)
            -> zap_over_floor(ZT_SPELL(ZT_FIRE), POT_OIL) */
-        yourzap = FALSE;  /* and leave zapverb as "blast" */
+        /* leave zapverb as "blast"; exploding_wand_typ was nonzero, so
+           'yourzap' is FALSE and the result will be "the blast" */
         exploding_wand_typ = 0; /* not actually an exploding wand */
     }