Revert "core: merge branch 'bg/restart-assume-rh1551958'"

This reverts commit cc1920d71470042c4e0837848da9183526b663d0, reversing
changes made to eb8257dea5802a004af9cccacb30af98440e2172.

This breaks restart, at least for Wi-Fi devices:

    #0  0x00007ffff5ee8771 in _g_log_abort (breakpoint=breakpoint@entry=1) at gmessages.c:554
    #1  0x00007ffff5ee9a5b in g_logv (log_domain=0x7ffff671a738 "GLib-GIO", log_level=G_LOG_LEVEL_CRITICAL, format=<optimized out>, args=args@entry=0x7fffffffd720) at gmessages.c:1362
    #2  0x00007ffff5ee9baf in g_log (log_domain=log_domain@entry=0x7ffff671a738 "GLib-GIO", log_level=log_level@entry=G_LOG_LEVEL_CRITICAL, format=format@entry=0x7ffff5f347ea "%s: assertion '%s' failed") at gmessages.c:1403
    #3  0x00007ffff5eea0f9 in g_return_if_fail_warning (log_domain=log_domain@entry=0x7ffff671a738 "GLib-GIO", pretty_function=pretty_function@entry=0x7ffff673fc10 <__func__.25628> "g_dbus_proxy_call_internal", expression=expression@entry=0x7ffff673fb1c "G_IS_DBUS_PROXY (proxy)") at gmessages.c:2702
    #4  0x00007ffff66cdc5f in g_dbus_proxy_call_internal (proxy=0x0, method_name=method_name@entry=0x555555810510 "Scan", parameters=0x555555c7a530, flags=flags@entry=G_DBUS_CALL_FLAGS_NONE, timeout_msec=timeout_msec@entry=-1, fd_list=fd_list@entry=0x0, cancellable=0x0, callback=0x55555574cb96 <scan_request_cb>, user_data=0x555555ac2220) at gdbusproxy.c:2664
    #5  0x00007ffff66cf686 in g_dbus_proxy_call (proxy=<optimized out>, method_name=method_name@entry=0x555555810510 "Scan", parameters=<optimized out>, flags=flags@entry=G_DBUS_CALL_FLAGS_NONE, timeout_msec=timeout_msec@entry=-1, cancellable=cancellable@entry=0x0, callback=0x55555574cb96 <scan_request_cb>, user_data=0x555555ac2220) at gdbusproxy.c:2970
    #6  0x000055555574e026 in nm_supplicant_interface_request_scan (self=0x555555ac2220 [NMSupplicantInterface], ssids=ssids@entry=0x0) at src/supplicant/nm-supplicant-interface.c:1821
    #7  0x00007fffe1038276 in request_wireless_scan (self=self@entry=0x555555c6ee60 [NMDeviceWifi], periodic=periodic@entry=0, force_if_scanning=force_if_scanning@entry=0, ssids=<optimized out>, ssids@entry=0x0) at src/devices/wifi/nm-device-wifi.c:1347
    #8  0x00007fffe1039011 in device_state_changed (device=0x555555c6ee60 [NMDeviceWifi], new_state=NM_DEVICE_STATE_DISCONNECTED, old_state=<optimized out>, reason=<optimized out>)
        at src/devices/wifi/nm-device-wifi.c:2998
    #9  0x00007ffff432ed1e in ffi_call_unix64 () at ../src/x86/unix64.S:76
    #10 0x00007ffff432e68f in ffi_call (cif=cif@entry=0x7fffffffdc70, fn=fn@entry=0x7fffe1038e1e <device_state_changed>, rvalue=<optimized out>, avalue=avalue@entry=0x7fffffffdb60)
        at ../src/x86/ffi64.c:525
    #15 0x00007ffff63db66f in <emit signal ??? on instance 0x555555c6ee60 [NMDeviceWifi]> (instance=instance@entry=0x555555c6ee60, signal_id=<optimized out>, detail=detail@entry=0)
        at gsignal.c:3447
        #11 0x00007ffff63bff39 in g_cclosure_marshal_generic (closure=0x555555c22ea0, return_gvalue=0x0, n_param_values=<optimized out>, param_values=<optimized out>, invocation_hint=<optimized out>, marshal_data=<optimized out>) at gclosure.c:1490
        #12 0x00007ffff63bf73d in g_closure_invoke (closure=0x555555c22ea0, return_value=0x0, n_param_values=4, param_values=0x7fffffffdea0, invocation_hint=0x7fffffffde20) at gclosure.c:804
        #13 0x00007ffff63d1f30 in signal_emit_unlocked_R (node=node@entry=0x555555c22750, detail=detail@entry=0, instance=instance@entry=0x555555c6ee60, emission_return=emission_return@entry=0x0, instance_and_params=instance_and_params@entry=0x7fffffffdea0) at gsignal.c:3673
        #14 0x00007ffff63dad05 in g_signal_emit_valist (instance=0x555555c6ee60, signal_id=<optimized out>, detail=0, var_args=var_args@entry=0x7fffffffe0b0) at gsignal.c:3391
    #16 0x00005555556f0f18 in _set_state_full (self=self@entry=0x555555c6ee60 [NMDeviceWifi], state=state@entry=NM_DEVICE_STATE_DISCONNECTED, reason=reason@entry=NM_DEVICE_STATE_REASON_CONNECTION_ASSUMED, quitting=quitting@entry=0) at src/devices/nm-device.c:13268
    #17 0x00005555556f1774 in nm_device_state_changed (self=self@entry=0x555555c6ee60 [NMDeviceWifi], state=state@entry=NM_DEVICE_STATE_DISCONNECTED, reason=reason@entry=NM_DEVICE_STATE_REASON_CONNECTION_ASSUMED) at src/devices/nm-device.c:13435
    #18 0x00005555555bcf95 in recheck_assume_connection (self=self@entry=0x555555b09140 [NMManager], device=device@entry=0x555555c6ee60 [NMDeviceWifi]) at src/nm-manager.c:2297
    #19 0x00005555555bd53e in _device_realize_finish (self=self@entry=0x555555b09140 [NMManager], device=device@entry=0x555555c6ee60 [NMDeviceWifi], plink=plink@entry=0x555555ae43d8)
        at src/nm-manager.c:2473
    #20 0x00005555555c01d0 in platform_link_added (self=self@entry=0x555555b09140 [NMManager], ifindex=<optimized out>, plink=plink@entry=0x555555ae43d8, guess_assume=<optimized out>, dev_state=<optimized out>) at src/nm-manager.c:2789
    #21 0x00005555555c0cec in platform_query_devices (self=self@entry=0x555555b09140 [NMManager]) at src/nm-manager.c:2901
    #22 0x00005555555c439e in nm_manager_start (self=0x555555b09140 [NMManager], error=<optimized out>) at src/nm-manager.c:5632
    #23 0x000055555558498e in main (argc=<optimized out>, argv=<optimized out>) at src/main.c:413

4 files changed, 70 insertions, 23 deletions

diff --git a/src/NetworkManagerUtils.c b/src/NetworkManagerUtils.c
index 72f2cbd568..12d46697ae 100644
--- a/src/NetworkManagerUtils.c
+++ b/src/NetworkManagerUtils.c
@@ -767,6 +767,10 @@ check_possible_match (NMConnection *orig,
  * @connections: a (optionally pre-sorted) list of connections from which to
  * find a matching connection to @original based on "inferrable" properties
  * @original: the #NMConnection to find a match for from @connections
+ * @indicated: whether the match is already hinted/indicated. That is the
+ *   case when we found the connection in the state file from a previous run.
+ *   In this case, we perform a relexed check, as we have a good hint
+ *   that the connection actually matches.
  * @device_has_carrier: pass %TRUE if the device that generated @original has
  * a carrier, %FALSE if not
  * @match_filter_func: a function to check whether each connection from @connections
@@ -786,6 +790,7 @@ check_possible_match (NMConnection *orig,
 NMConnection *
 nm_utils_match_connection (NMConnection *const*connections,
                            NMConnection *original,
+                           gboolean indicated,
                            gboolean device_has_carrier,
                            gint64 default_v4_metric,
                            gint64 default_v6_metric,
@@ -806,7 +811,24 @@ nm_utils_match_connection (NMConnection *const*connections,
 				continue;
 		}
 
-		if (!nm_connection_diff (original, candidate, NM_SETTING_COMPARE_FLAG_INFERRABLE, &diffs)) {
+		if (indicated) {
+			NMSettingConnection *s_orig, *s_cand;
+
+			s_orig = nm_connection_get_setting_connection (original);
+			s_cand = nm_connection_get_setting_connection (candidate);
+
+			/* It is indicated that this connection matches. Assume we have
+			 * a match, but check for particular differences that let us
+			 * reject the candidate. */
+			if (!nm_streq0 (nm_setting_connection_get_connection_type (s_orig),
+			                nm_setting_connection_get_connection_type (s_cand)))
+				continue;
+			if (!nm_streq0 (nm_setting_connection_get_slave_type (s_orig),
+			                nm_setting_connection_get_slave_type (s_cand)))
+				continue;
+
+			/* this is good enough for a match */
+		} else if (!nm_connection_diff (original, candidate, NM_SETTING_COMPARE_FLAG_INFERRABLE, &diffs)) {
 			if (!best_match) {
 				best_match = check_possible_match (original, candidate, diffs, device_has_carrier,
 				                                   default_v4_metric, default_v6_metric);
diff --git a/src/NetworkManagerUtils.h b/src/NetworkManagerUtils.h
index 54ba10fe28..13bdb67e85 100644
--- a/src/NetworkManagerUtils.h
+++ b/src/NetworkManagerUtils.h
@@ -41,6 +41,7 @@ typedef gboolean (NMUtilsMatchFilterFunc) (NMConnection *connection, gpointer us
 
 NMConnection *nm_utils_match_connection (NMConnection *const*connections,
                                          NMConnection *original,
+                                         gboolean indicated,
                                          gboolean device_has_carrier,
                                          gint64 default_v4_metric,
                                          gint64 default_v6_metric,
diff --git a/src/nm-manager.c b/src/nm-manager.c
index b64cb39aa4..c82347e27e 100644
--- a/src/nm-manager.c
+++ b/src/nm-manager.c
@@ -2125,12 +2125,12 @@ get_existing_connection (NMManager *self,
                          gboolean *out_generated)
 {
 	NMManagerPrivate *priv = NM_MANAGER_GET_PRIVATE (self);
-	NMConnection *connection = NULL;
+	gs_unref_object NMConnection *connection = NULL;
 	NMSettingsConnection *added = NULL;
 	GError *error = NULL;
 	NMDevice *master = NULL;
 	int ifindex = nm_device_get_ifindex (device);
-	NMSettingsConnection *matched = NULL;
+	NMSettingsConnection *matched;
 	NMSettingsConnection *connection_checked = NULL;
 	gboolean assume_state_guess_assume = FALSE;
 	const char *assume_state_connection_uuid = NULL;
@@ -2161,31 +2161,54 @@ get_existing_connection (NMManager *self,
 		}
 	}
 
+	/* The core of the API is nm_device_generate_connection() function and
+	 * update_connection() virtual method and the convenient connection_type
+	 * class attribute. Subclasses supporting the new API must have
+	 * update_connection() implemented, otherwise nm_device_generate_connection()
+	 * returns NULL.
+	 */
+	connection = nm_device_generate_connection (device, master, &maybe_later, &error);
+	if (!connection) {
+		if (!maybe_later)
+			nm_device_assume_state_reset (device);
+		_LOG2D (LOGD_DEVICE, device, "assume: cannot generate connection: %s",
+		        error->message);
+		g_error_free (error);
+		return NULL;
+	}
+
 	nm_device_assume_state_get (device,
 	                            &assume_state_guess_assume,
 	                            &assume_state_connection_uuid);
 
+	/* Now we need to compare the generated connection to each configured
+	 * connection. The comparison function is the heart of the connection
+	 * assumption implementation and it must compare the connections very
+	 * carefully to sort out various corner cases. Also, the comparison is
+	 * not entirely symmetric.
+	 *
+	 * When no configured connection matches the generated connection, we keep
+	 * the generated connection instead.
+	 */
 	if (   assume_state_connection_uuid
 	    && (connection_checked = nm_settings_get_connection_by_uuid (priv->settings, assume_state_connection_uuid))
-	    && nm_device_check_connection_compatible (device, NM_CONNECTION (connection_checked)))
-		matched = connection_checked;
-
-	if (!matched) {
-		/* The core of the API is nm_device_generate_connection() function and
-		 * update_connection() virtual method and the convenient connection_type
-		 * class attribute. Subclasses supporting the new API must have
-		 * update_connection() implemented, otherwise nm_device_generate_connection()
-		 * returns NULL.
-		 */
-		connection = nm_device_generate_connection (device, master, &maybe_later, &error);
-		if (!connection) {
-			if (!maybe_later)
-				nm_device_assume_state_reset (device);
-			_LOG2D (LOGD_DEVICE, device, "assume: cannot generate connection: %s", error->message);
-			g_error_free (error);
-			return NULL;
-		}
-	}
+	    && !active_connection_find_first (self, connection_checked, NULL,
+	                                      NM_ACTIVE_CONNECTION_STATE_DEACTIVATING)
+	    && nm_device_check_connection_compatible (device, NM_CONNECTION (connection_checked))) {
+		NMConnection *const connections[] = {
+			NM_CONNECTION (connection_checked),
+			NULL,
+		};
+
+		matched = NM_SETTINGS_CONNECTION (nm_utils_match_connection (connections,
+		                                                             connection,
+		                                                             TRUE,
+		                                                             nm_device_has_carrier (device),
+		                                                             nm_device_get_route_metric (device, AF_INET),
+		                                                             nm_device_get_route_metric (device, AF_INET6),
+		                                                             NULL, NULL));
+	} else
+		matched = NULL;
 
 	if (!matched && assume_state_guess_assume) {
 		gs_free NMSettingsConnection **connections = NULL;
@@ -2209,6 +2232,7 @@ get_existing_connection (NMManager *self,
 
 			matched = NM_SETTINGS_CONNECTION (nm_utils_match_connection ((NMConnection *const*) connections,
 			                                                             connection,
+			                                                             FALSE,
 			                                                             nm_device_has_carrier (device),
 			                                                             nm_device_get_route_metric (device, AF_INET),
 			                                                             nm_device_get_route_metric (device, AF_INET6),
diff --git a/src/tests/test-general.c b/src/tests/test-general.c
index 5276d9b0e3..632f2c33cc 100644
--- a/src/tests/test-general.c
+++ b/src/tests/test-general.c
@@ -359,7 +359,7 @@ _match_connection (GSList *connections,
 	}
 	list[i] = NULL;
 
-	return nm_utils_match_connection (list, original, device_has_carrier, default_v4_metric, default_v6_metric, NULL, NULL);
+	return nm_utils_match_connection (list, original, FALSE, device_has_carrier, default_v4_metric, default_v6_metric, NULL, NULL);
 }
 
 static void