Add assistance to fire-command

Allows the fire-command to autowield a launcher; it will now
do either swapweapon or wield an appropriate launcher, if you
have ammo quivered.

This assistance can be turned off with the fireassist boolean option.

Adds a rudimentary command queue, which allows the code to add keys
or extended commands into the queue, and they're executed as if
the user did them.  Time passes normally when doing the queue,
and the queue will get cleared if hero is interrupted.

src/cmd.c

@@ -228,6 +228,76 @@ set_occupation(int (*fn)(void), const char *txt, int xtime)
     return;
 }
 
+/* add extended command function to the command queue */
+void
+cmdq_add_ec(int (*fn)(void))
+{
+    struct _cmd_queue *tmp = (struct _cmd_queue *)alloc(sizeof(struct _cmd_queue));
+    struct _cmd_queue *cq = g.command_queue;
+
+    tmp->typ = CMDQ_EXTCMD;
+    tmp->ec_entry = ext_func_tab_from_func(fn);
+    tmp->next = NULL;
+
+    while (cq && cq->next)
+        cq = cq->next;
+
+    if (cq)
+        cq->next = tmp;
+    else
+        g.command_queue = tmp;
+}
+
+/* add a key to the command queue */
+void
+cmdq_add_key(char key)
+{
+    struct _cmd_queue *tmp = (struct _cmd_queue *)alloc(sizeof(struct _cmd_queue));
+    struct _cmd_queue *cq = g.command_queue;
+
+    tmp->typ = CMDQ_KEY;
+    tmp->key = key;
+    tmp->next = NULL;
+
+    while (cq && cq->next)
+        cq = cq->next;
+
+    if (cq)
+        cq->next = tmp;
+    else
+        g.command_queue = tmp;
+}
+
+/* pop off the topmost command from the command queue.
+ * caller is responsible for freeing the returned _cmd_queue.
+ */
+struct _cmd_queue *
+cmdq_pop(void)
+{
+    struct _cmd_queue *tmp = g.command_queue;
+
+    if (tmp) {
+        g.command_queue = tmp->next;
+        tmp->next = NULL;
+    }
+    return tmp;
+}
+
+/* clear all commands from the command queue */
+void
+cmdq_clear(void)
+{
+    struct _cmd_queue *tmp = g.command_queue;
+    struct _cmd_queue *tmp2;
+
+    while (tmp) {
+        tmp2 = tmp->next;
+        free(tmp);
+        tmp = tmp2;
+    }
+    g.command_queue = NULL;
+}
+
 static char popch(void);
 
 static char
@@ -2482,6 +2552,18 @@ dokeylist(void)
     destroy_nhwindow(datawin);
 }
 
+const struct ext_func_tab *
+ext_func_tab_from_func(int (*fn)(void))
+{
+    const struct ext_func_tab *extcmd;
+
+    for (extcmd = extcmdlist; extcmd->ef_txt; ++extcmd)
+        if (extcmd->ef_funct == fn)
+            return extcmd;
+
+    return NULL;
+}
+
 char
 cmd_from_func(int (*fn)(void))
 {
@@ -3350,13 +3432,30 @@ rhack(char *cmd)
     int spkey;
     boolean prefix_seen, bad_command,
         firsttime = (cmd == 0);
+    struct _cmd_queue *cmdq = NULL;
+    const struct ext_func_tab *cmdq_ec = NULL;
 
     iflags.menu_requested = FALSE;
 #ifdef SAFERHANGUP
     if (g.program_state.done_hup)
         end_of_input();
 #endif
-    if (firsttime) {
+    if ((cmdq = cmdq_pop()) != 0) {
+        /* doing queued commands */
+        if (cmdq->typ == CMDQ_KEY) {
+            static char commandline[2];
+
+            if (!cmd)
+                cmd = commandline;
+            cmd[0] = cmdq->key;
+            cmd[1] = '\0';
+        } else if (cmdq->typ == CMDQ_EXTCMD) {
+            cmdq_ec = cmdq->ec_entry;
+        }
+        free(cmdq);
+        if (cmdq_ec)
+            goto do_cmdq_extcmd;
+    } else if (firsttime) {
         g.context.nopick = 0;
         cmd = parse();
     }
@@ -3539,14 +3638,22 @@ rhack(char *cmd)
         register const struct ext_func_tab *tlist;
         int res, (*func)(void);
 
+do_cmdq_extcmd:
+        if (cmdq_ec)
+            tlist = cmdq_ec;
+        else
+            tlist = g.Cmd.commands[*cmd & 0xff];
+
         /* current - use *cmd to directly index cmdlist array */
-        if ((tlist = g.Cmd.commands[*cmd & 0xff]) != 0) {
+        if (tlist != 0) {
             if (!wizard && (tlist->flags & WIZMODECMD)) {
                 You_cant("do that!");
                 res = 0;
+                cmdq_clear();
             } else if (u.uburied && !(tlist->flags & IFBURIED)) {
                 You_cant("do that while you are buried!");
                 res = 0;
+                cmdq_clear();
             } else {
                 /* we discard 'const' because some compilers seem to have
                    trouble with the pointer passed to set_occupation() */
@@ -3575,6 +3682,7 @@ rhack(char *cmd)
 
         if (!prefix_seen || !help_dir(c1, spkey, "Invalid direction key!"))
             Norep("Unknown command '%s'.", expcmd);
+        cmdq_clear();
     }
     /* didn't move */
     g.context.move = FALSE;