From c0a1ed9c41895136b3195f10486773b201c17c1b Mon Sep 17 00:00:00 2001
From: PatR <rankin@nethack.org>
Date: Thu, 16 Jan 2025 12:51:40 -0800
Subject: [PATCH] another stab at stumble_onto_mimic

The unreliable sanity check is removed.
---
 src/pager.c |  6 +++++-
 src/uhitm.c | 18 +++++++-----------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/src/pager.c b/src/pager.c
index eb5956061..e964554f2 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -289,7 +289,11 @@ object_from_map(
     boolean fakeobj = FALSE, mimic_obj = FALSE;
     struct monst *mtmp;
     struct obj *otmp;
-    int glyphotyp = glyph_to_obj(glyph);
+    int glyphotyp = glyph_is_object(glyph) ? glyph_to_obj(glyph)
+                    /* if not an object, probably a detected chest trap */
+                    : glyph_is_cmap(glyph) /* assume trapped chest|door */
+                      ? (sobj_at(CHEST, x, y) ? CHEST : LARGE_BOX)
+                      : STRANGE_OBJECT;
 
     *obj_p = (struct obj *) 0;
     /* TODO: check inside containers in case glyph came from detection */
diff --git a/src/uhitm.c b/src/uhitm.c
index b3b470c00..dc7264af1 100644
--- a/src/uhitm.c
+++ b/src/uhitm.c
@@ -6068,26 +6068,22 @@ that_is_a_mimic(
         else if (M_AP_TYPE(mtmp) == M_AP_MONSTER)
             what = a_monnam(mtmp); /* differs from what was sensed */
     } else {
-        int glyph = glyph_at(u.ux + u.dx, u.uy + u.dy);
+        coordxy x = u.ux + u.dx, y = u.uy + u.dy;
+        int glyph = glyph_at(x, y);
 
         if (glyph_is_cmap(glyph)) {
             int sym = glyph_to_cmap(glyph);
 
-#ifdef EXTRA_SANITY_CHECKS
-            if (iflags.sanity_check && (int) mtmp->mappearance != sym)
-                impossible("mimic appearance %u does not match"
-                           " map feature %d (glyph=%d)",
-                           mtmp->mappearance, sym, glyph);
-#endif
-            /* note: defsyms[stairs] yields singular "staircase {up|down}" */
-            Snprintf(fmtbuf, sizeof fmtbuf, "That %s actually is %%s!",
-                     defsyms[sym].explanation);
+            if (M_AP_TYPE(mtmp) == M_AP_FURNITURE
+                || (M_AP_TYPE(mtmp) == M_AP_OBJECT && sym == S_trapped_chest))
+                Snprintf(fmtbuf, sizeof fmtbuf, "That %s actually is %%s!",
+                         defsyms[sym].explanation);
         } else if (glyph_is_object(glyph)) {
             boolean fakeobj;
             const char *otmp_name;
             struct obj *otmp = NULL;
 
-            fakeobj = object_from_map(glyph, mtmp->mx, mtmp->my, &otmp);
+            fakeobj = object_from_map(glyph, x, y, &otmp);
             otmp_name = (otmp && otmp->otyp != STRANGE_OBJECT)
                         ? simpleonames(otmp) : "strange object";
             Snprintf(fmtbuf, sizeof fmtbuf, "%s %s %s %%s!",