From af58efe67aee871131039955de99989b3f2da3b6 Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Sat, 26 Oct 2019 06:40:16 -0700
Subject: [PATCH] SCP: Fix SHOW command parsing to properly valiidate argument
 cases

As originally reported in #758
---
 scp.c | 44 +++++++++++++++-----------------------------
 1 file changed, 15 insertions(+), 29 deletions(-)

diff --git a/scp.c b/scp.c
index f3f73416..d90f963c 100644
--- a/scp.c
+++ b/scp.c
@@ -3125,7 +3125,7 @@ if (dptr->modifiers) {
         if ((!mptr->disp) || (!mptr->pstring) || !(*mptr->pstring))
             continue;
         fprint_header (st, &found, header);
-        sprintf (buf, "show %s %s%s", sim_dname (dptr), mptr->pstring, MODMASK(mptr,MTAB_SHP) ? "=arg" : "");
+        sprintf (buf, "show %s %s%s", sim_dname (dptr), mptr->pstring, MODMASK(mptr,MTAB_SHP) ? "{=arg}" : "");
         fprintf (st, "%-30s\t%s\n", buf, mptr->help ? mptr->help : "");
         }
     }
@@ -5310,11 +5310,6 @@ while (*cptr != 0) {                                    /* do all mods */
                     }
                 else if (!mptr->desc)                   /* value desc? */
                     break;
-//                else if (mptr->mask & MTAB_VAL) {     /* take a value? */
-//                    if (!cvptr) return SCPE_MISVAL;   /* none? error */
-//                    r = dep_reg (0, cvptr, (REG *) mptr->desc, 0);
-//                    if (r != SCPE_OK) return r;
-//                    }
                 else if (cvptr)                         /* = value? */
                     return SCPE_ARG;
                 else *((int32 *) mptr->desc) = mptr->match;
@@ -5529,9 +5524,9 @@ if ((dptr = find_dev (gbuf))) {                         /* device match? */
     }
 else if ((dptr = find_unit (gbuf, &uptr))) {            /* unit match? */
     if (uptr == NULL)                                   /* invalid unit */
-        return SCPE_NXUN;
+        return sim_messagef (SCPE_NXUN, "Non-existent unit: %s\n", gbuf);
     if (uptr->flags & UNIT_DIS)                         /* disabled? */
-        return SCPE_UDIS;
+        return sim_messagef (SCPE_UDIS, "Unit disabled: %s\n", gbuf);
     shtb = show_unit_tab;                               /* global table */
     lvl = MTAB_VUN;                                     /* unit match */
     GET_SWITCHES (cptr);                                /* get more switches */
@@ -5544,7 +5539,7 @@ else {
     if (sim_dflt_dev->modifiers) {
         if ((cvptr = strchr (gbuf, '=')))               /* = value? */
             *cvptr++ = 0;
-        for (mptr = sim_dflt_dev->modifiers; mptr->mask != 0; mptr++) {
+        for (mptr = sim_dflt_dev->modifiers; mptr && (mptr->mask != 0); mptr++) {
             if ((((mptr->mask & MTAB_VDV) == MTAB_VDV) &&
                  (mptr->pstring && (MATCH_CMD (gbuf, mptr->pstring) == 0))) ||
                 (!(mptr->mask & MTAB_VDV) && (mptr->mstring && (MATCH_CMD (gbuf, mptr->mstring) == 0)))) {
@@ -5561,7 +5556,7 @@ else {
         if ((shptr = find_shtab (show_dev_tab, gbuf)))  /* global match? */
             return shptr->action (ofile, sim_dflt_dev, uptr, shptr->arg, cptr);
         else
-            return SCPE_NXDEV;                          /* no match */
+            return sim_messagef (SCPE_NXDEV, "Non-existent device: %s\n", gbuf);/* no match */
         }
     }
 
@@ -5581,13 +5576,9 @@ while (*cptr != 0) {                                    /* do all mods */
             ((mptr->mask & lvl) == lvl): (MTAB_VUN & lvl)) &&
             ((mptr->disp && mptr->pstring &&            /* named disp? */
             (MATCH_CMD (gbuf, mptr->pstring) == 0))
- //           ||
- //           ((mptr->mask & MTAB_VAL) &&                 /* named value? */
- //           mptr->mstring &&
- //           (MATCH_CMD (gbuf, mptr->mstring) == 0)))
             )) {
-            if (cvptr && !(mptr->mask & MTAB_SHP))
-                return SCPE_ARG;
+            if (cvptr && !MODMASK(mptr,MTAB_SHP))
+                return sim_messagef (SCPE_ARG, "Invalid Argument: %s=%s\n", gbuf, cvptr);
             show_one_mod (ofile, dptr, uptr, mptr, cvptr, 1);
             break;
             }                                           /* end if */
@@ -5600,10 +5591,12 @@ while (*cptr != 0) {                                    /* do all mods */
             if (r != SCPE_OK)
                 return r;
             }
-        else if (!dptr->modifiers)                      /* no modifiers? */
-            return SCPE_NOPARAM;
-        else
-            return SCPE_NXPAR;
+        else {
+            if (!dptr->modifiers)                       /* no modifiers? */
+                return sim_messagef (SCPE_NOPARAM, "%s device has no parameters\n", dptr->name);
+            else
+                return sim_messagef (SCPE_NXPAR, "Non-existent parameter: %s\n", gbuf);
+            }
         }                                               /* end if */
     }                                                   /* end while */
 return SCPE_OK;
@@ -6255,18 +6248,11 @@ t_stat show_one_mod (FILE *st, DEVICE *dptr, UNIT *uptr, MTAB *mptr,
     CONST char *cptr, int32 flag)
 {
 t_stat r = SCPE_OK;
-//t_value val;
 
 if (mptr->disp)
     r = mptr->disp (st, uptr, mptr->match, (CONST void *)(cptr? cptr: mptr->desc));
-//else if ((mptr->mask & MTAB_XTD) && (mptr->mask & MTAB_VAL)) {
-//    REG *rptr = (REG *) mptr->desc;
-//    fprintf (st, "%s=", mptr->pstring);
-//    val = get_rval (rptr, 0);
-//    fprint_val (st, val, rptr->radix, rptr->width,
-//        rptr->flags & REG_FMT);
-//    }
-else fputs (mptr->pstring, st);
+else
+    fputs (mptr->pstring, st);
 if ((r == SCPE_OK) && (flag && !((mptr->mask & MTAB_XTD) && MODMASK(mptr,MTAB_NMO))))
     fputc ('\n', st);
 return r;