fix github issue #729 - edibility_prompts()

Issue #729 by argrath points out that one of the checks in
edibility_prompts() couldn't work.

For the next-meal effect after reading a blessed scroll of food
detection, the check whether a corpse was tainted but not dangerous
because the hero had sickness resistance could never be evaluated.
An earlier condition would cause the routine to return before
reaching that check.

Move it sooner, even though doing so violates the "order by most
to least dangerous" guideline.  It was either that or eliminate it
altogether.

edibility_prompts() had a lot of repetitive code that has now been
condensed.

Simplify acid blob corpse handling--for all of eating, not just for
edibility_prompts()--by treating that as "never rots" so that the
'rotted' variable always stays 0.  Now checks for that variable
being greater than some threshold don't need to include "and not an
acid blob corpse" as an exception.  A side-effect of this change is
that not only do they never become tainted, they'll no longer yield
the "you feel sick" outcome when they're old but not old enough to
exceed the tainted threshold.

Bug fix:  edibility testing stopped warning about green slimes.
That worked in 3.6.x, but 3.7 changed the 'cadaver' variable to
exclude them so the check for eating a glob of green slime could no
longer be reached.

Fixes #729

doc/fixes3-7-0.txt

@@ -1160,6 +1160,9 @@ items obtained via wishing while blind were erroneously being marked as 'seen
 	up close' so behaving differently from items picked up off the floor
 corpses of neuter monsters had random chance to be flagged as female so would
 	only stack with others that made the same random choice
+one-shot food testing ability conferred by blessed scroll of food detection
+	didn't warn about globs of green slime because the relevant code was
+	only executed for corpses, eggs, and tins, not for globs
 
 curses: 'msg_window' option wasn't functional for curses unless the binary
 	also included tty support

src/eat.c

@@ -52,9 +52,13 @@ static int tin_ok(struct obj *);
 #define flesh_petrifies(pm) (touch_petrifies(pm) || (pm) == &mons[PM_MEDUSA])
 
 /* Rider corpses are treated as non-rotting so that attempting to eat one
-   will be sure to reach the stage of eating where that meal is fatal */
+   will be sure to reach the stage of eating where that meal is fatal;
+   acid blob corpses eventually rot away to nothing but before that happens
+   they can be sacrificed regardless of age which implies that they never
+   become rotten */
 #define nonrotting_corpse(mnum) \
-    ((mnum) == PM_LIZARD || (mnum) == PM_LICHEN || is_rider(&mons[mnum]))
+    ((mnum) == PM_LIZARD || (mnum) == PM_LICHEN || is_rider(&mons[mnum]) \
+     || (mnum) == PM_ACID_BLOB)
 
 /* non-rotting non-corpses; unlike lizard corpses, these items will behave
    as if rotten if they are cursed (fortune cookies handled elsewhere) */
@@ -1772,8 +1776,7 @@ eatcorpse(struct obj *otmp)
     }
 
     /* 3.7: globs don't become tainted, they shrink away */
-    if (mnum != PM_ACID_BLOB && !glob && !stoneable && !slimeable
+    if (!glob && !stoneable && !slimeable && rotted > 5L) {
-        && rotted > 5L) {
         boolean cannibal = maybe_cannibal(mnum, FALSE);
 
         /* tp++; -- early return makes this unnecessary */
@@ -1815,6 +1818,7 @@ eatcorpse(struct obj *otmp)
                    KILLED_BY_AN);
         } else
             You("seem unaffected by the poison.");
+
     /* now any corpse left too long will make you mildly ill */
     } else if ((rotted > 5L || (rotted > 3L && rn2(5))) && !Sick_resistance) {
         tp++;
@@ -1860,11 +1864,11 @@ eatcorpse(struct obj *otmp)
                                && herbivorous(g.youmonst.data))
                             : (carnivorous(g.youmonst.data)
                                && !herbivorous(g.youmonst.data))),
-            palatable = ((vegetarian(&mons[mnum])
+                palatable = ((vegetarian(&mons[mnum])
-                          ? herbivorous(g.youmonst.data)
+                              ? herbivorous(g.youmonst.data)
-                          : carnivorous(g.youmonst.data))
+                              : carnivorous(g.youmonst.data))
-                         && rn2(10)
+                             && rn2(10)
-                         && ((rotted < 1) ? TRUE : !rn2((int)rotted+1)));
+                             && (rotted < 1 || !rn2((int) rotted + 1)));
         const char *pmxnam = food_xname(otmp, FALSE);
 
         if (!strncmpi(pmxnam, "the ", 4))
@@ -2474,7 +2478,7 @@ edibility_prompts(struct obj *otmp)
      * or dangerous and avoid it.
      */
     char buf[BUFSZ], foodsmell[BUFSZ],
-         it_or_they[QBUFSZ], eat_it_anyway[QBUFSZ];
+         it_or_they[QBUFSZ];
     /* 3.7: decaying globs don't become tainted anymore; in 3.6, they did */
     boolean cadaver = (otmp->otyp == CORPSE), stoneorslime = FALSE;
     int material = objects[otmp->otyp].oc_material, mnum = otmp->corpsenm;
@@ -2482,10 +2486,9 @@ edibility_prompts(struct obj *otmp)
 
     Strcpy(foodsmell, Tobjnam(otmp, "smell"));
     Strcpy(it_or_they, (otmp->quan == 1L) ? "it" : "they");
-    Sprintf(eat_it_anyway, "Eat %s anyway?",
-            (otmp->quan == 1L) ? "it" : "one");
 
-    if (cadaver || otmp->otyp == EGG || otmp->otyp == TIN) {
+    if (cadaver || otmp->otyp == EGG || otmp->otyp == TIN
+        || otmp->otyp == GLOB_OF_GREEN_SLIME) {
         /* These checks must match those in eatcorpse() */
         stoneorslime = (mnum >= LOW_PM
                         && flesh_petrifies(&mons[mnum])
@@ -2512,109 +2515,64 @@ edibility_prompts(struct obj *otmp)
      * These problems with food should be checked in
      * order from most detrimental to least detrimental.
      */
-    if (cadaver && mnum != PM_ACID_BLOB && rotted > 5L && !Sick_resistance) {
+    buf[0] = '\0';
+    if (cadaver && rotted > 5L && !Sick_resistance) {
         /* Tainted meat */
-        Snprintf(buf, sizeof(buf), "%s like %s could be tainted!  %s",
+        Snprintf(buf, sizeof buf, "%s like %s could be tainted!",
-                 foodsmell, it_or_they, eat_it_anyway);
+                 foodsmell, it_or_they);
-        if (yn_function(buf, ynchars, 'n') == 'n')
+    } else if (stoneorslime) {
-            return 1;
+        Snprintf(buf, sizeof buf,
-        else
+                 "%s like %s could be something very dangerous!",
-            return 2;
+                 foodsmell, it_or_they);
-    }
+    } else if (cadaver && rotted > 5L && Sick_resistance) {
-    if (stoneorslime) {
+        /* Tainted meat with Sick_resistance (testing for that is
-        Snprintf(buf, sizeof(buf),
+           redundant; we don't get this far for !Sick_resistance)
-                 "%s like %s could be something very dangerous!  %s",
+           needs to be done now even though there is no danger because
-                 foodsmell, it_or_they, eat_it_anyway);
+           it can't match after the rotten (cadaver && rotted > 3) test */
-        if (yn_function(buf, ynchars, 'n') == 'n')
+        Snprintf(buf, sizeof buf, "%s like %s could be tainted.",
-            return 1;
+                 foodsmell, it_or_they);
-        else
+    } else if (otmp->orotten || (cadaver && rotted > 3L)) {
-            return 2;
-    }
-    if (otmp->orotten || (cadaver && rotted > 3L)) {
         /* Rotten */
-        Snprintf(buf, sizeof(buf), "%s like %s could be rotten! %s",
+        Snprintf(buf, sizeof buf, "%s like %s could be rotten!",
-                 foodsmell, it_or_they, eat_it_anyway);
+                 foodsmell, it_or_they);
-        if (yn_function(buf, ynchars, 'n') == 'n')
+    } else if (cadaver && poisonous(&mons[mnum]) && !Poison_resistance) {
-            return 1;
-        else
-            return 2;
-    }
-    if (cadaver && poisonous(&mons[mnum]) && !Poison_resistance) {
         /* poisonous */
-        Snprintf(buf, sizeof(buf), "%s like %s might be poisonous!  %s",
+        Snprintf(buf, sizeof buf, "%s like %s might be poisonous!",
-                 foodsmell, it_or_they, eat_it_anyway);
+                 foodsmell, it_or_they);
-        if (yn_function(buf, ynchars, 'n') == 'n')
+    } else if (otmp->otyp == APPLE && otmp->cursed && !Sleep_resistance) {
-            return 1;
-        else
-            return 2;
-    }
-    if (otmp->otyp == APPLE && otmp->cursed && !Sleep_resistance) {
         /* causes sleep, for long enough to be dangerous */
-        Snprintf(buf, sizeof(buf), "%s like %s might have been poisoned.  %s",
+        Snprintf(buf, sizeof buf, "%s like %s might have been poisoned.",
-                 foodsmell, it_or_they, eat_it_anyway);
+                 foodsmell, it_or_they);
-        return (yn_function(buf, ynchars, 'n') == 'n') ? 1 : 2;
+    } else if (cadaver && !vegetarian(&mons[mnum])
-    }
+               && !u.uconduct.unvegetarian && Role_if(PM_MONK)) {
-    if (cadaver && !vegetarian(&mons[mnum]) && !u.uconduct.unvegetarian
+        Snprintf(buf, sizeof buf, "%s unhealthy.", foodsmell);
-        && Role_if(PM_MONK)) {
+    } else if (cadaver && acidic(&mons[mnum]) && !Acid_resistance) {
-        Snprintf(buf, sizeof(buf), "%s unhealthy.  %s", foodsmell,
+        Snprintf(buf, sizeof buf, "%s rather acidic.", foodsmell);
-                 eat_it_anyway);
+    } else if (Upolyd && u.umonnum == PM_RUST_MONSTER && is_metallic(otmp)
-        if (yn_function(buf, ynchars, 'n') == 'n')
+               && otmp->oerodeproof) {
-            return 1;
+        Snprintf(buf, sizeof buf, "%s disgusting to you right now.",
-        else
+                 foodsmell);
-            return 2;
-    }
-    if (cadaver && acidic(&mons[mnum]) && !Acid_resistance) {
-        Snprintf(buf, sizeof(buf), "%s rather acidic.  %s",
-                 foodsmell, eat_it_anyway);
-        if (yn_function(buf, ynchars, 'n') == 'n')
-            return 1;
-        else
-            return 2;
-    }
-    if (Upolyd && u.umonnum == PM_RUST_MONSTER && is_metallic(otmp)
-        && otmp->oerodeproof) {
-        Snprintf(buf, sizeof(buf), "%s disgusting to you right now.  %s",
-                 foodsmell, eat_it_anyway);
-        if (yn_function(buf, ynchars, 'n') == 'n')
-            return 1;
-        else
-            return 2;
-    }
 
     /*
      * Breaks conduct, but otherwise safe.
      */
-    if (!u.uconduct.unvegan
+    } else if (!u.uconduct.unvegan
-        && ((material == LEATHER || material == BONE
+               && ((material == LEATHER || material == BONE
-             || material == DRAGON_HIDE || material == WAX)
+                    || material == DRAGON_HIDE || material == WAX)
-            || (cadaver && !vegan(&mons[mnum])))) {
+                   || (cadaver && !vegan(&mons[mnum])))) {
-        Snprintf(buf, sizeof(buf), "%s foul and unfamiliar to you.  %s",
+        Snprintf(buf, sizeof buf, "%s foul and unfamiliar to you.",
-                 foodsmell, eat_it_anyway);
+                 foodsmell);
-        if (yn_function(buf, ynchars, 'n') == 'n')
+    } else if (!u.uconduct.unvegetarian
-            return 1;
+               && ((material == LEATHER || material == BONE
-        else
+                    || material == DRAGON_HIDE)
-            return 2;
+                   || (cadaver && !vegetarian(&mons[mnum])))) {
-    }
+        Snprintf(buf, sizeof buf, "%s unfamiliar to you.", foodsmell);
-    if (!u.uconduct.unvegetarian
-        && ((material == LEATHER || material == BONE
-             || material == DRAGON_HIDE)
-            || (cadaver && !vegetarian(&mons[mnum])))) {
-        Snprintf(buf, sizeof(buf), "%s unfamiliar to you.  %s",
-                 foodsmell, eat_it_anyway);
-        if (yn_function(buf, ynchars, 'n') == 'n')
-            return 1;
-        else
-            return 2;
     }
 
-    if (cadaver && mnum != PM_ACID_BLOB && rotted > 5L && Sick_resistance) {
+    if (*buf) {
-        /* Tainted meat with Sick_resistance */
+        Snprintf(eos(buf), sizeof buf - strlen(buf), "  Eat %s anyway?",
-        Snprintf(buf, sizeof(buf), "%s like %s could be tainted!  %s",
+                 (otmp->quan == 1L) ? "it" : "one");
-                 foodsmell, it_or_they, eat_it_anyway);
+        return (yn_function(buf, ynchars, 'n') == 'n') ? 1 : 2;
-        if (yn_function(buf, ynchars, 'n') == 'n')
-            return 1;
-        else
-            return 2;
     }
     return 0;
 }