From 00f45d62aed0b377e077262aa903ac02d5642fde Mon Sep 17 00:00:00 2001
From: PatR <rankin@nethack.org>
Date: Sun, 15 Oct 2023 15:04:07 -0700
Subject: [PATCH] data.base lookup for inventory item actions

Simplify the code that checks whether '/' should be included in an
inventory item action menu.  Initially it was overloading the
'supplemental_name' argument to provide an alternate return value and
when that was discarded, some of the convolutions it needed stuck
around.  Since there was no primary return value, just switch to that.
---
 src/pager.c | 41 ++++++++++++++++++++---------------------
 1 file changed, 20 insertions(+), 21 deletions(-)

diff --git a/src/pager.c b/src/pager.c
index d115779dd..23216e0e3 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -15,7 +15,7 @@ static void trap_description(char *, int, coordxy, coordxy);
 static void look_at_object(char *, coordxy, coordxy, int);
 static void look_at_monster(char *, char *, struct monst *, coordxy, coordxy);
 static struct permonst *lookat(coordxy, coordxy, char *, char *);
-static void checkfile(char *, struct permonst *, unsigned, char *);
+static boolean checkfile(char *, struct permonst *, unsigned, char *);
 static int add_cmap_descr(int, int, int, int, coord,
                           const char *, const char *,
                           boolean *, const char **, char *);
@@ -52,9 +52,6 @@ enum checkfileflags {
     chkfilIaCheck  = 4,
 };
 
-/* checkfile() sets this in lieu of a return value if given IaCheck flag */
-static char checkfile_hack; /* once set, always 'F' or 'T' */
-
 static const char invisexplain[] = "remembered, unseen, creature",
            altinvisexplain[] = "unseen creature"; /* for clairvoyance */
 
@@ -697,12 +694,10 @@ ia_checkfile(struct obj *otmp)
 {
     char itemnam[BUFSZ];
 
-    checkfile_hack = 'F'; /* checkfile() might change it */
     /* singular() of xname() of otmp is what "/i" looks up */
     Strcpy(itemnam, singular(otmp, xname));
-    checkfile(itemnam, (struct permonst *) 0,
-              chkfilIaCheck | chkfilDontAsk, (char *) 0);
-    return (checkfile_hack == 'T');
+    return checkfile(itemnam, (struct permonst *) 0,
+                     chkfilIaCheck | chkfilDontAsk, (char *) 0);
 }
 
 /*
@@ -714,8 +709,10 @@ ia_checkfile(struct obj *otmp)
  *       must not be changed directly, e.g. via lcase(). We want to force
  *       lcase() for data.base lookup so that we can have a clean key.
  *       Therefore, we create a copy of inp _just_ for data.base lookup.
+ *
+ * Returns True if an entry is found, False otherwise.
  */
-static void
+static boolean
 checkfile(
     char *inp, /* string to look up */
     struct permonst *pm, /* monster type to look up (overrides 'inp') */
@@ -730,11 +727,12 @@ checkfile(
             ia_checking = (chkflags & chkfilIaCheck) != 0;
     unsigned long txt_offset = 0L;
     winid datawin = WIN_ERR;
+    boolean res = FALSE;
 
     fp = dlb_fopen(DATAFILE, "r");
     if (!fp) {
         pline("Cannot open 'data' file!");
-        return;
+        return res;
     }
     /* If someone passed us garbage, prevent fault. */
     if (!inp || strlen(inp) > (BUFSZ - 1)) {
@@ -961,10 +959,10 @@ checkfile(
                         pline("? Seek error on 'data' file!");
                         goto checkfile_done;
                     }
-                    if (ia_checking) {
-                        checkfile_hack = 'T';
+                    res = TRUE;
+                    if (ia_checking)
                         goto checkfile_done;
-                    }
+
                     datawin = create_nhwindow(NHW_MENU);
                     for (i = 0; i < entry_count; i++) {
                         /* room for 1-tab or 8-space prefix + BUFSZ-1 + \0 */
@@ -1013,7 +1011,7 @@ checkfile(
     if (datawin != WIN_ERR)
         destroy_nhwindow(datawin);
     (void) dlb_fclose(fp);
-    return;
+    return res;
 }
 
 /* extracted from do_screen_description() */
@@ -1615,8 +1613,8 @@ do_look(int mode, coord *click_cc)
                     break;
                 }
             if (*out_str)
-                checkfile(out_str, pm, chkfilUsrTyped | chkfilDontAsk,
-                          (char *) 0);
+                (void) checkfile(out_str, pm, chkfilUsrTyped | chkfilDontAsk,
+                                 (char *) 0);
             return ECMD_OK;
           }
         case '?':
@@ -1630,8 +1628,8 @@ do_look(int mode, coord *click_cc)
                 return ECMD_OK;
 
             if (out_str[1]) { /* user typed in a complete string */
-                checkfile(out_str, pm,  chkfilUsrTyped | chkfilDontAsk,
-                          (char *) 0);
+                (void) checkfile(out_str, pm,  chkfilUsrTyped | chkfilDontAsk,
+                                 (char *) 0);
                 return ECMD_OK;
             }
             sym = out_str[0];
@@ -1732,9 +1730,10 @@ do_look(int mode, coord *click_cc)
 
                 supplemental_name[0] = '\0';
                 Strcpy(temp_buf, firstmatch);
-                checkfile(temp_buf, pm,
-                          (ans == LOOK_VERBOSE) ? chkfilDontAsk : chkfilNone,
-                          supplemental_name);
+                (void) checkfile(temp_buf, pm,
+                                 (ans == LOOK_VERBOSE) ? chkfilDontAsk
+                                                       : chkfilNone,
+                                 supplemental_name);
                 if (supplemental_pm)
                     do_supplemental_info(supplemental_name, supplemental_pm,
                                          (boolean) (ans == LOOK_VERBOSE));