Fix subtle bugs when installing/loading extensions

app/src/main/java/eu/kanade/tachiyomi/extension/util/ExtensionInstallActivity.kt

@@ -4,6 +4,7 @@ import android.app.Activity
 import android.content.Intent
 import android.os.Bundle
 import eu.kanade.tachiyomi.extension.ExtensionManager
+import eu.kanade.tachiyomi.util.toast
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
 
@@ -21,7 +22,13 @@ class ExtensionInstallActivity : Activity() {
                 .putExtra(Intent.EXTRA_RETURN_RESULT, true)
                 .setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
 
-        startActivityForResult(installIntent, INSTALL_REQUEST_CODE)
+        try {
+            startActivityForResult(installIntent, INSTALL_REQUEST_CODE)
+        } catch (error: Exception) {
+            // Either install package can't be found (probably bots) or there's a security exception
+            // with the download manager. Nothing we can workaround.
+            toast(error.message)
+        }
     }
 
     override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {

app/src/main/java/eu/kanade/tachiyomi/extension/util/ExtensionLoader.kt

@@ -66,7 +66,12 @@ internal object ExtensionLoader {
      * contains the required feature flag before trying to load it.
      */
     fun loadExtensionFromPkgName(context: Context, pkgName: String): LoadResult {
-        val pkgInfo = context.packageManager.getPackageInfo(pkgName, PACKAGE_FLAGS)
+        val pkgInfo = try {
+            context.packageManager.getPackageInfo(pkgName, PACKAGE_FLAGS)
+        } catch (error: PackageManager.NameNotFoundException) {
+            // Unlikely, but the package may have been uninstalled at this point
+            return LoadResult.Error(error)
+        }
         if (!isPackageAnExtension(pkgInfo)) {
             return LoadResult.Error("Tried to load a package that wasn't a extension")
         }
@@ -83,9 +88,15 @@ internal object ExtensionLoader {
     private fun loadExtension(context: Context, pkgName: String, pkgInfo: PackageInfo): LoadResult {
         val pkgManager = context.packageManager
 
-        val appInfo = pkgManager.getApplicationInfo(pkgName, PackageManager.GET_META_DATA)
+        val appInfo = try {
+            pkgManager.getApplicationInfo(pkgName, PackageManager.GET_META_DATA)
+        } catch (error: PackageManager.NameNotFoundException) {
+            // Unlikely, but the package may have been uninstalled at this point
+            return LoadResult.Error(error)
+        }
 
-        val extName = pkgManager.getApplicationLabel(appInfo).toString().substringAfter("Tachiyomi: ")
+        val extName = pkgManager.getApplicationLabel(appInfo)?.toString()
+            .orEmpty().substringAfter("Tachiyomi: ")
         val versionName = pkgInfo.versionName
         val versionCode = pkgInfo.versionCode