fix(nav): restore broken traceroute map navigation (#5104)

core/navigation/src/commonTest/kotlin/org/meshtastic/core/navigation/MultiBackstackTest.kt

@@ -111,4 +111,35 @@ class MultiBackstackTest {
         assertEquals(2, multiBackstack.activeBackStack.size)
         assertEquals(SettingsRoute.About, multiBackstack.activeBackStack.last())
     }
+
+    @Test
+    fun `handleDeepLink from different tab switches tab and sets stack`() {
+        // Start on Connections tab
+        val startTab = TopLevelDestination.Connections.route
+        val multiBackstack = MultiBackstack(startTab)
+
+        val connectionsStack = NavBackStack<NavKey>().apply { addAll(listOf(TopLevelDestination.Connections.route)) }
+        val nodesStack = NavBackStack<NavKey>().apply { addAll(listOf(TopLevelDestination.Nodes.route)) }
+
+        multiBackstack.backStacks =
+            mapOf(
+                TopLevelDestination.Connections.route to connectionsStack,
+                TopLevelDestination.Nodes.route to nodesStack,
+            )
+
+        // Verify we start on Connections
+        assertEquals(TopLevelDestination.Connections.route, multiBackstack.currentTabRoute)
+
+        // Deep-link to a TracerouteMap on the Nodes tab (this is the exact pattern
+        // MeshtasticAppShell uses for traceroute alert "View on Map")
+        val tracerouteMap = NodeDetailRoute.TracerouteMap(destNum = 100, requestId = 42, logUuid = "abc")
+        multiBackstack.handleDeepLink(listOf(NodesRoute.NodesGraph, tracerouteMap))
+
+        // Should have switched to the Nodes tab
+        assertEquals(TopLevelDestination.Nodes.route, multiBackstack.currentTabRoute)
+        // Stack should contain the graph root + the traceroute map route
+        assertEquals(2, multiBackstack.activeBackStack.size)
+        assertEquals(NodesRoute.NodesGraph, multiBackstack.activeBackStack.first())
+        assertEquals(tracerouteMap, multiBackstack.activeBackStack.last())
+    }
 }

core/ui/src/commonMain/kotlin/org/meshtastic/core/ui/component/MeshtasticAppShell.kt

@@ -21,6 +21,7 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.ui.Modifier
 import org.meshtastic.core.navigation.MultiBackstack
 import org.meshtastic.core.navigation.NodeDetailRoute
+import org.meshtastic.core.navigation.NodesRoute
 import org.meshtastic.core.ui.viewmodel.UIViewModel
 
 /**
@@ -43,8 +44,11 @@ fun MeshtasticAppShell(
     MeshtasticCommonAppSetup(
         uiViewModel = uiViewModel,
         onNavigateToTracerouteMap = { destNum, requestId, logUuid ->
-            multiBackstack.activeBackStack.add(
-                NodeDetailRoute.TracerouteMap(destNum = destNum, requestId = requestId, logUuid = logUuid),
+            multiBackstack.handleDeepLink(
+                listOf(
+                    NodesRoute.NodesGraph,
+                    NodeDetailRoute.TracerouteMap(destNum = destNum, requestId = requestId, logUuid = logUuid),
+                ),
             )
         },
     )

core/ui/src/commonMain/kotlin/org/meshtastic/core/ui/component/TracerouteAlertHandler.kt

@@ -26,9 +26,11 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import kotlinx.coroutines.launch
 import org.meshtastic.core.resources.Res
 import org.meshtastic.core.resources.okay
 import org.meshtastic.core.resources.traceroute
@@ -52,6 +54,7 @@ fun TracerouteAlertHandler(
     val traceRouteResponse by uiViewModel.tracerouteResponse.collectAsStateWithLifecycle(null)
     var dismissedTracerouteRequestId by remember { mutableStateOf<Int?>(null) }
     val colorScheme = MaterialTheme.colorScheme
+    val scope = rememberCoroutineScope()
 
     LaunchedEffect(traceRouteResponse, dismissedTracerouteRequestId) {
         val response = traceRouteResponse
@@ -83,8 +86,10 @@ fun TracerouteAlertHandler(
                         dismissedTracerouteRequestId = response.requestId
                         onNavigateToMap(response.destinationNodeNum, response.requestId, response.logUuid)
                     } else {
-                        uiViewModel.showAlert(titleRes = Res.string.traceroute, messageRes = errorRes)
                         uiViewModel.clearTracerouteResponse()
+                        // Post the error alert after the current alert is dismissed to avoid
+                        // the wrapping dismissAlert() in AlertManager immediately clearing it.
+                        scope.launch { uiViewModel.showAlert(titleRes = Res.string.traceroute, messageRes = errorRes) }
                     }
                 },
                 dismissTextRes = Res.string.okay,

core/ui/src/commonTest/kotlin/org/meshtastic/core/ui/util/AlertManagerTest.kt

@@ -68,4 +68,27 @@ class AlertManagerTest {
         assertEquals(true, dismissClicked)
         assertNull(alertManager.currentAlert.value)
     }
+
+    @Test
+    fun showAlert_inside_onConfirm_is_dismissed_by_wrapping_dismissAlert() {
+        // Documents the known race condition: AlertManager wraps onConfirm to call
+        // dismissAlert() AFTER the user callback, so a showAlert() inside onConfirm
+        // gets immediately cleared. Callers must defer via launch {} to work around this.
+        alertManager.showAlert(
+            title = "First",
+            onConfirm = {
+                // This simulates an error path where onConfirm shows a follow-up alert
+                alertManager.showAlert(title = "Second", message = "Error details")
+            },
+        )
+
+        // Trigger the wrapped onConfirm (user callback + dismissAlert)
+        alertManager.currentAlert.value?.onConfirm?.invoke()
+
+        // The second alert is wiped by dismissAlert() — currentAlert is null
+        assertNull(
+            alertManager.currentAlert.value,
+            "showAlert inside onConfirm is cleared by the wrapping dismissAlert; callers must defer via launch {}",
+        )
+    }
 }

feature/node/src/commonMain/kotlin/org/meshtastic/feature/node/metrics/MetricsViewModel.kt

@@ -277,7 +277,6 @@ open class MetricsViewModel(
         responseLogUuid: String,
         overlay: TracerouteOverlay?,
         onViewOnMap: (Int, String) -> Unit,
-        onShowError: (StringResource) -> Unit,
     ) {
         viewModelScope.launch {
             val snapshotPositions = tracerouteSnapshotRepository.getSnapshotPositions(responseLogUuid).first()
@@ -300,7 +299,11 @@ open class MetricsViewModel(
                         )
                     val errorRes = availability.toMessageRes()
                     if (errorRes != null) {
-                        onShowError(errorRes)
+                        // Post the error alert after the current alert is dismissed to avoid
+                        // the wrapping dismissAlert() in AlertManager immediately clearing it.
+                        viewModelScope.launch {
+                            alertManager.showAlert(titleRes = Res.string.traceroute, messageRes = errorRes)
+                        }
                     } else {
                         onViewOnMap(requestId, responseLogUuid)
                     }

feature/node/src/commonMain/kotlin/org/meshtastic/feature/node/metrics/TracerouteLog.kt

@@ -361,7 +361,6 @@ private fun showTracerouteDetail(
         responseLogUuid = result.uuid,
         overlay = overlay,
         onViewOnMap = onViewOnMap,
-        onShowError = {},
     )
 }