Fix crash when a deep link opens with no browser available (#23121)

* Guard the deep link browser hand-off against a missing browser

A tracking link whose redirect target the app can't handle is passed to
an external browser with an implicit ACTION_VIEW intent. On devices with
no app able to handle a web link the intent fails to resolve and the deep
link receiver dies before it can tell the user anything. Report the
missing handler with a toast instead, matching how the rest of the app
opens external URLs.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Finish the deep link receiver when the browser hand-off fails

The receiver activity has no UI of its own and nothing on the OpenInBrowser
path finishes it, so after the toast the user was left on an empty screen
until they pressed back. Verified on device with every web link handler
disabled: the toast shows and the launcher comes back.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: adalpari

RELEASE-NOTES.txt

@@ -5,6 +5,7 @@
 * [*] You can now browse Google Photos (albums, collections, and search) when adding photos or videos from your device.
 * [**] Fixed media uploads and the Media Library failing on Jetpack-connected self-hosted sites that have Application Passwords disabled.
 * [*] Stats now refresh when you return to the screen, so your latest data appears without a manual pull-to-refresh. [https://github.com/wordpress-mobile/WordPress-Android/pull/23112]
+* [*] Links from emails that open outside the app now show a clear message when no browser is available, instead of closing the app.
 
 26.9
 -----

WordPress/src/main/java/org/wordpress/android/ui/deeplinks/DeepLinkNavigator.kt

@@ -1,7 +1,9 @@
 package org.wordpress.android.ui.deeplinks
 
+import android.content.ActivityNotFoundException
 import android.content.Intent
 import androidx.appcompat.app.AppCompatActivity
+import org.wordpress.android.R
 import org.wordpress.android.fluxc.model.SiteModel
 import org.wordpress.android.ui.ActivityLauncher
 import org.wordpress.android.ui.ActivityNavigator
@@ -34,6 +36,9 @@ import org.wordpress.android.ui.sitecreation.misc.SiteCreationSource.DEEP_LINK
 import org.wordpress.android.ui.sitemonitor.SiteMonitorType
 import org.wordpress.android.ui.stats.StatsTimeframe
 import org.wordpress.android.ui.stats.refresh.utils.StatsLaunchedFrom
+import org.wordpress.android.util.AppLog
+import org.wordpress.android.util.AppLog.T.UTILS
+import org.wordpress.android.util.ToastUtils
 import org.wordpress.android.util.UriWrapper
 import javax.inject.Inject
 
@@ -52,11 +57,7 @@ class DeepLinkNavigator
                 activity,
                 navigateAction.site
             )
-            is OpenInBrowser -> {
-                @SuppressWarnings("UnsafeImplicitIntentLaunch")
-                val browserIntent = Intent(Intent.ACTION_VIEW, navigateAction.uri.uri)
-                activity.startActivity(browserIntent)
-            }
+            is OpenInBrowser -> openInBrowser(activity, navigateAction.uri)
             is OpenEditorForPost -> ActivityLauncher.openEditorForPostInNewStack(
                 activity,
                 navigateAction.site,
@@ -125,6 +126,26 @@ class DeepLinkNavigator
         }
     }
 
+    /**
+     * Opens the uri with an external browser. The device may have no app able to handle a web link (no browser
+     * installed, browser disabled or restricted by a work profile), so the missing handler is reported to the user
+     * instead of crashing the deep link entry point.
+     *
+     * The receiver activity has no UI of its own, so it is finished when the hand-off fails. Otherwise the user is
+     * left on an empty screen after the toast. The toast still shows, since it does not depend on the activity.
+     */
+    private fun openInBrowser(activity: AppCompatActivity, uri: UriWrapper) {
+        @SuppressWarnings("UnsafeImplicitIntentLaunch")
+        val browserIntent = Intent(Intent.ACTION_VIEW, uri.uri)
+        try {
+            activity.startActivity(browserIntent)
+        } catch (e: ActivityNotFoundException) {
+            ToastUtils.showToast(activity, R.string.cant_open_url, ToastUtils.Duration.LONG)
+            AppLog.e(UTILS, "No app available on the device to open the deep link: $uri", e)
+            activity.finish()
+        }
+    }
+
     sealed class NavigateAction {
         object LoginForResult : NavigateAction()
         data class OpenInBrowser(val uri: UriWrapper) : NavigateAction()