config.c: loop over backends list for protocol selector.

Similarly to the previous commit, this is one fewer place where I need
to make a handwritten change with each new protocol.

be_none.c

@@ -6,6 +6,8 @@
 #include <stdio.h>
 #include "putty.h"
 
+const int be_default_protocol = -1;
+
 const struct BackendVtable *const backends[] = {
     NULL
 };

config.c

@@ -1535,23 +1535,34 @@ void setup_config_box(struct controlbox *b, bool midsession,
         hp->port = c;
         ctrl_columns(s, 1, 100);
 
-        if (!backend_vt_from_proto(PROT_SSH)) {
+        c = ctrl_radiobuttons(s, "Connection type:", NO_SHORTCUT, 4,
-            ctrl_radiobuttons(s, "Connection type:", NO_SHORTCUT, 3,
                               HELPCTX(session_hostname),
-                              config_protocolbuttons_handler, P(hp),
+                              config_protocolbuttons_handler, P(hp), NULL);
-                              "Raw", 'w', I(PROT_RAW),
+        c->radio.buttons = sresize(c->radio.buttons, PROTOCOL_LIMIT, char *);
-                              "Telnet", 't', I(PROT_TELNET),
+        c->radio.shortcuts = sresize(c->radio.shortcuts, PROTOCOL_LIMIT, char);
-                              "Rlogin", 'i', I(PROT_RLOGIN),
+        c->radio.buttondata = sresize(c->radio.buttondata, PROTOCOL_LIMIT,
-                              NULL);
+                                      intorptr);
-        } else {
+        assert(c->radio.nbuttons == 0);
-            ctrl_radiobuttons(s, "Connection type:", NO_SHORTCUT, 4,
+        for (int pass = 0; pass < 4; pass++) {
-                              HELPCTX(session_hostname),
+            for (size_t i = 0; backends[i]; i++) {
-                              config_protocolbuttons_handler, P(hp),
+                int pass_needed = (
-                              "Raw", 'w', I(PROT_RAW),
+                    backends[i]->protocol == be_default_protocol ? 0 :
-                              "Telnet", 't', I(PROT_TELNET),
+                    backends[i]->protocol == PROT_SERIAL ? 1 :
-                              "Rlogin", 'i', I(PROT_RLOGIN),
+                    backends[i]->protocol == PROT_RAW ? 2 : 3);
-                              "SSH", 's', I(PROT_SSH),
+                if (pass != pass_needed)
-                              NULL);
+                    continue;
+
+                c->radio.buttons[c->radio.nbuttons] =
+                    dupstr(backends[i]->displayname);
+                c->radio.shortcuts[c->radio.nbuttons] =
+                    (backends[i]->protocol == PROT_SSH ? 's' :
+                     backends[i]->protocol == PROT_SERIAL ? 'r' :
+                     backends[i]->protocol == PROT_RAW ? 'w' :
+                     NO_SHORTCUT);
+                c->radio.buttondata[c->radio.nbuttons] =
+                    I(backends[i]->protocol);
+                c->radio.nbuttons++;
+            }
         }
     }
 

putty.h

@@ -368,7 +368,8 @@ enum {
     PROT_RAW, PROT_TELNET, PROT_RLOGIN, PROT_SSH,
     /* PROT_SERIAL is supported on a subset of platforms, but it doesn't
      * hurt to define it globally. */
-    PROT_SERIAL
+    PROT_SERIAL,
+    PROTOCOL_LIMIT, /* upper bound on number of protocols */
 };
 
 enum {

sercfg.c

@@ -128,39 +128,6 @@ void ser_setup_config_box(struct controlbox *b, bool midsession,
                           int parity_mask, int flow_mask)
 {
     struct controlset *s;
-    union control *c;
-
-    if (!midsession) {
-        int i;
-
-        /*
-         * Add the serial back end to the protocols list at the
-         * top of the config box.
-         */
-        s = ctrl_getset(b, "Session", "hostport",
-                        "Specify the destination you want to connect to");
-
-        for (i = 0; i < s->ncontrols; i++) {
-            c = s->ctrls[i];
-            if (c->generic.type == CTRL_RADIO &&
-                c->generic.handler == config_protocolbuttons_handler) {
-                c->radio.nbuttons++;
-                c->radio.ncolumns++;
-                c->radio.buttons =
-                    sresize(c->radio.buttons, c->radio.nbuttons, char *);
-                c->radio.buttons[c->radio.nbuttons-1] =
-                    dupstr("Serial");
-                c->radio.buttondata =
-                    sresize(c->radio.buttondata, c->radio.nbuttons, intorptr);
-                c->radio.buttondata[c->radio.nbuttons-1] = I(PROT_SERIAL);
-                if (c->radio.shortcuts) {
-                    c->radio.shortcuts =
-                        sresize(c->radio.shortcuts, c->radio.nbuttons, char);
-                    c->radio.shortcuts[c->radio.nbuttons-1] = 'r';
-                }
-            }
-        }
-    }
 
     /*
      * Entirely new Connection/Serial panel for serial port