Centralise defaults for non-saved options.

These are now specified in conf.h and filled in by automated code,
which means test_conf can make sure we didn't forget to provide them.

The default for a mapping type (not that we currently have any unsaved
ones) is expected to be empty.

Also, while adding test_conf checks, I realised I hadn't filled in the
rest of the comment in conf.h. Belatedly updated that.

conf.h

@@ -9,6 +9,22 @@
  *  - SUBKEY_TYPE: if the primary key goes with a subkey (that is, the
  *    primary key identifies some mapping from subkeys to values), the
  *    data type of the subkey
+ *  - DEFAULT_INT, DEFAULT_STR, DEFAULT_BOOL: the default value for
+ *    the key, if no save data is available. Must match VALUE_TYPE, if
+ *    the key has no subkey. Otherwise, no default is permitted, and
+ *    the default value of the mapping is assumed to be empty (and if
+ *    not, then LOAD_CUSTOM code must override that).
+ *  - SAVE_KEYWORD: the keyword used for the option in the Windows
+ *    registry or ~/.putty/sessions save files.
+ *  - STORAGE_ENUM: for int-typed settings with no subkeys, this
+ *    identifies an enumeration in conf-enums.h which maps internal
+ *    values of the setting in the Conf to values in the saved data.
+ *  - LOAD_CUSTOM, SAVE_CUSTOM: suppress automated loading or saving
+ *    (respectively) of this setting, in favour of manual code in
+ *    settings.c load_open_settings() or save_open_settings()
+ *    respectively.
+ *  - NOT_SAVED: indicate that this setting is not part of saved
+ *    session data at all.
  */
 
 CONF_OPTION(host,
@@ -150,6 +166,7 @@ CONF_OPTION(remote_cmd2,
      * by user configuration, or loaded or saved.
      */
     VALUE_TYPE(STR),
+    DEFAULT_STR(""),
     NOT_SAVED,
 )
 CONF_OPTION(nopty,
@@ -255,6 +272,7 @@ CONF_OPTION(ssh_simple,
      * user configuration, or loaded or saved.
      */
     VALUE_TYPE(BOOL),
+    DEFAULT_BOOL(false),
     NOT_SAVED,
 )
 CONF_OPTION(ssh_connection_sharing,
@@ -349,14 +367,16 @@ CONF_OPTION(ssh_subsys, /* run a subsystem rather than a command */
      * configuration, or loaded or saved.
      */
     VALUE_TYPE(BOOL),
+    DEFAULT_BOOL(false),
     NOT_SAVED,
 )
-CONF_OPTION(ssh_subsys2, /* fallback to go with remote_cmd_ptr2 */
+CONF_OPTION(ssh_subsys2, /* fallback to go with remote_cmd2 */
     /*
      * Only set internally by PSCP and PSFTP; never set by user
      * configuration, or loaded or saved.
      */
     VALUE_TYPE(BOOL),
+    DEFAULT_BOOL(false),
     NOT_SAVED,
 )
 CONF_OPTION(ssh_no_shell, /* avoid running a shell */
@@ -371,6 +391,7 @@ CONF_OPTION(ssh_nc_host, /* host to connect to in `nc' mode */
      * also never loaded or saved.
      */
     VALUE_TYPE(STR),
+    DEFAULT_STR(""),
     NOT_SAVED,
 )
 CONF_OPTION(ssh_nc_port, /* port to connect to in `nc' mode */
@@ -380,6 +401,7 @@ CONF_OPTION(ssh_nc_port, /* port to connect to in `nc' mode */
      * also never loaded or saved.
      */
     VALUE_TYPE(INT),
+    DEFAULT_INT(0),
     NOT_SAVED,
 )
 

settings.c

@@ -670,15 +670,27 @@ void load_open_settings(settings_r *sesskey, Conf *conf)
     int i;
     char *prot;
 
-    conf_set_bool(conf, CONF_ssh_subsys, false); /* FIXME: load this properly */
-    conf_set_str(conf, CONF_remote_cmd, "");
-    conf_set_str(conf, CONF_remote_cmd2, "");
-    conf_set_str(conf, CONF_ssh_nc_host, "");
-
     /* Load the settings simple enough to handle automatically */
     for (size_t key = 0; key < N_CONFIG_OPTIONS; key++) {
         const ConfKeyInfo *info = &conf_key_info[key];
-        if (!info->load_custom && !info->not_saved) {
+        if (info->not_saved) {
+            /* Mappings are assumed to default to empty */
+            if (info->subkey_type == CONF_TYPE_NONE) {
+                switch (info->value_type) {
+                  case CONF_TYPE_STR:
+                    conf_set_str(conf, key, info->default_value.sval);
+                    break;
+                  case CONF_TYPE_INT:
+                    conf_set_int(conf, key, info->default_value.ival);
+                    break;
+                  case CONF_TYPE_BOOL:
+                    conf_set_bool(conf, key, info->default_value.bval);
+                    break;
+                  default:
+                    unreachable("bad key type in load_open_settings");
+                }
+            }
+        } else if (!info->load_custom) {
             /* Mappings are handled individually below */
             assert(info->subkey_type == CONF_TYPE_NONE);
             switch (info->value_type) {
@@ -994,7 +1006,6 @@ void load_open_settings(settings_r *sesskey, Conf *conf)
                 conf_set_int(conf, CONF_sshbug_hmac2, FORCE_ON);
         }
     }
-    conf_set_bool(conf, CONF_ssh_simple, false);
     gppmap(sesskey, "SSHManualHostKeys", conf, CONF_ssh_manual_hostkeys);
 }
 

test/test_conf.c

@@ -822,6 +822,7 @@ void test_conf_key_info(void)
         const char *name;
         bool got_value_type : 1;
         bool got_subkey_type : 1;
+        bool got_default : 1;
         bool got_default_int : 1;
         bool got_default_str : 1;
         bool got_default_bool : 1;
@@ -835,9 +836,9 @@ void test_conf_key_info(void)
 #define CONF_OPTION(id, ...) { .name = "CONF_" #id, __VA_ARGS__ },
 #define VALUE_TYPE(x) .got_value_type = true
 #define SUBKEY_TYPE(x) .got_subkey_type = true
-#define DEFAULT_INT(x) .got_default_int = true
+#define DEFAULT_INT(x) .got_default_int = true, .got_default = true
-#define DEFAULT_STR(x) .got_default_str = true
+#define DEFAULT_STR(x) .got_default_str = true, .got_default = true
-#define DEFAULT_BOOL(x) .got_default_bool = true
+#define DEFAULT_BOOL(x) .got_default_bool = true, .got_default = true
 #define SAVE_KEYWORD(x) .got_save_keyword = true
 #define STORAGE_ENUM(x) .got_storage_enum = true
 #define SAVE_CUSTOM .save_custom = true
@@ -857,6 +858,11 @@ void test_conf_key_info(void)
             nfails++;
         }
 
+        if (td->got_default && info->subkey_type != CONF_TYPE_NONE) {
+            fprintf(stderr, "%s: is a mapping but has a default\n", td->name);
+            nfails++;
+        }
+
         if ((td->got_default_int && info->value_type != CONF_TYPE_INT) ||
             (td->got_default_str && info->value_type != CONF_TYPE_STR) ||
             (td->got_default_bool && info->value_type != CONF_TYPE_BOOL)) {
@@ -871,6 +877,12 @@ void test_conf_key_info(void)
         }
 
         if (td->not_saved) {
+            if (!td->got_default && info->subkey_type == CONF_TYPE_NONE) {
+                fprintf(stderr, "%s: simple unsaved setting but has no "
+                        "default\n", td->name);
+                nfails++;
+            }
+
             if (td->got_save_keyword) {
                 fprintf(stderr, "%s: not saved but has SAVE_KEYWORD\n",
                         td->name);