Pop the fragment in the backstack when custom tab is active and the onCloseWindow window callback of the BrowserChromeClient is triggered

app/src/androidTest/java/com/duckduckgo/app/browser/BrowserTabViewModelTest.kt

@@ -2924,11 +2924,27 @@ class BrowserTabViewModelTest {
         }
 
     @Test
-    fun whenCloseCurrentTabSelectedThenTabDeletedFromRepository() =
+    fun whenCloseCurrentTabSelectedAndNotInCustomTabThenTabDeletedFromRepository() =
         runTest {
+            testee.setIsCustomTab(false)
             givenOneActiveTabSelected()
             testee.closeCurrentTab()
+            verify(mockCommandObserver, atLeastOnce()).onChanged(commandCaptor.capture())
             verify(mockTabRepository).deleteTabAndSelectSource(selectedTabLiveData.value!!.tabId)
+            val command = commandCaptor.allValues.find { it is Command.NavigateBackInCustomTab }
+            assertNull(command)
+        }
+
+    @Test
+    fun whenCloseCurrentTabAndCustomTabAndCustomTabScreenEmitNavigateBackInCustomTabCommand() =
+        runTest {
+            testee.setIsCustomTab(true)
+            testee.closeCurrentTab()
+            verify(mockTabRepository, never()).deleteTabAndSelectSource(any())
+            verify(mockCommandObserver, atLeastOnce()).onChanged(commandCaptor.capture())
+            val command = commandCaptor.allValues.find { it is Command.NavigateBackInCustomTab }
+            assertNotNull(command)
+            assertTrue(command is Command.NavigateBackInCustomTab)
         }
 
     @Test

app/src/main/java/com/duckduckgo/app/browser/BrowserTabFragment.kt

@@ -2080,6 +2080,12 @@ class BrowserTabFragment :
                 browserActivity?.launchNewTab()
             }
 
+            is Command.NavigateBackInCustomTab -> {
+                if (isActiveCustomTab() && parentFragmentManager.backStackEntryCount > 0) {
+                    parentFragmentManager.popBackStack()
+                }
+            }
+
             is Command.ShowSavedSiteAddedConfirmation -> savedSiteAdded(it.savedSiteChangedViewState)
             is Command.ShowEditSavedSiteDialog -> editSavedSite(it.savedSiteChangedViewState)
             is Command.DeleteFavoriteConfirmation ->

app/src/main/java/com/duckduckgo/app/browser/BrowserTabViewModel.kt

@@ -1317,8 +1317,12 @@ class BrowserTabViewModel @Inject constructor(
         }
 
     override fun closeCurrentTab() {
-        viewModelScope.launch {
-            removeCurrentTabFromRepository()
+        if (isCustomTabScreen) {
+            command.value = Command.NavigateBackInCustomTab
+        } else {
+            viewModelScope.launch {
+                removeCurrentTabFromRepository()
+            }
         }
     }
 

app/src/main/java/com/duckduckgo/app/browser/commands/Command.kt

@@ -67,6 +67,8 @@ sealed class Command {
         val query: String,
     ) : Command()
 
+    object NavigateBackInCustomTab : Command()
+
     data object LaunchNewTab : Command()
 
     data object ResetHistory : Command()