fix(note-editor): retain note type when copying and preserve field data

AnkiDroid/src/main/java/com/ichi2/anki/NoteEditorFragment.kt

@@ -153,6 +153,8 @@ import com.ichi2.anki.snackbar.BaseSnackbarBuilderProvider
 import com.ichi2.anki.snackbar.SnackbarBuilder
 import com.ichi2.anki.snackbar.showSnackbar
 import com.ichi2.anki.ui.setupNoteTypeSpinner
+import com.ichi2.anki.utils.ext.getLongOrNull
+import com.ichi2.anki.utils.ext.indexOfOrNull
 import com.ichi2.anki.utils.ext.sharedPrefs
 import com.ichi2.anki.utils.ext.showDialogFragment
 import com.ichi2.anki.utils.ext.window
@@ -874,6 +876,12 @@ class NoteEditorFragment :
         if (addNote) {
             noteTypeSpinner!!.onItemSelectedListener = SetNoteTypeListener()
             requireAnkiActivity().setToolbarTitle(R.string.menu_add)
+
+            // if a specific note type id was provided in the arguments select it in the spinner
+            val noteTypeId: Long? = requireArguments().getLongOrNull(EXTRA_NOTE_TYPE_ID)
+            val noteTypeIdIndex: Int? = noteTypeId?.let { allNoteTypeIds?.indexOfOrNull(it) }
+            noteTypeIdIndex?.let { noteTypeSpinner?.setSelection(it) }
+
             // set information transferred by intent
             var contents: String? = null
             val tags = requireArguments().getStringArray(EXTRA_TAGS)
@@ -1317,6 +1325,8 @@ class NoteEditorFragment :
 
         // treat add new note and edit existing note independently
         if (addNote) {
+            // truncate the fields to the actual size the notetype supports
+            editorNote!!.fields = editorNote!!.fields.take(editorNote!!.notetype.fields.length()).toMutableList()
             // load all of the fields into the note
             for (f in editFields!!) {
                 updateField(f)
@@ -1620,7 +1630,8 @@ class NoteEditorFragment :
     }
 
     fun copyNote() {
-        launchNoteEditor(NoteEditorLauncher.CopyNote(deckId, fieldsText, selectedTags)) { }
+        val noteTypeId = currentlySelectedNotetype?.id ?: editorNote?.notetype?.id
+        launchNoteEditor(NoteEditorLauncher.CopyNote(deckId, fieldsText, selectedTags, noteTypeId)) { }
     }
 
     private fun launchNoteEditor(
@@ -2483,7 +2494,17 @@ class NoteEditorFragment :
             if (note == null || addNote) {
                 getColUnsafe.run {
                     val notetype = notetypes.current()
-                    Note.fromNotetypeId(this@run, notetype.id)
+                    val newNote = Note.fromNotetypeId(this@run, notetype.id)
+                    editorNote?.let {
+                        if (editorNote!!.fields.size > newNote.fields.size) {
+                            newNote.fields = editorNote!!.fields.toMutableList()
+                        } else {
+                            editorNote!!.fields.forEachIndexed { i, field ->
+                                newNote.fields[i] = field
+                            }
+                        }
+                    }
+                    newNote
                 }
             } else {
                 note
@@ -2882,7 +2903,9 @@ class NoteEditorFragment :
         if (!getColUnsafe.config.getBool(ConfigKey.Bool.ADDING_DEFAULTS_TO_CURRENT_DECK)) {
             deckId = getColUnsafe.defaultsForAdding().deckId
         }
-
+        for (f in editFields!!) {
+            updateField(f)
+        }
         refreshNoteData(FieldChangeType.changeFieldCount(shouldReplaceNewlines()))
         setDuplicateFieldStyles()
     }
@@ -3092,6 +3115,7 @@ class NoteEditorFragment :
         const val RELOAD_REQUIRED_EXTRA_KEY = "reloadRequired"
         const val EXTRA_IMG_OCCLUSION = "image_uri"
         const val IN_CARD_BROWSER_ACTIVITY = "inCardBrowserActivity"
+        const val EXTRA_NOTE_TYPE_ID = "NOTE_TYPE_ID"
 
         // calling activity
         enum class NoteEditorCaller(

AnkiDroid/src/main/java/com/ichi2/anki/noteeditor/NoteEditorLauncher.kt

@@ -30,7 +30,9 @@ import com.ichi2.anki.NoteEditorFragment.Companion.NoteEditorCaller
 import com.ichi2.anki.browser.CardBrowserViewModel
 import com.ichi2.anki.libanki.CardId
 import com.ichi2.anki.libanki.DeckId
+import com.ichi2.anki.libanki.NoteTypeId
 import com.ichi2.anki.utils.Destination
+import com.ichi2.anki.utils.ext.bundleOfNotNull
 
 /**
  * Defines various configurations for opening the NoteEditor fragment with specific data or actions.
@@ -206,12 +208,14 @@ sealed interface NoteEditorLauncher : Destination {
         val deckId: DeckId,
         val fieldsText: String,
         val tags: List<String>? = null,
+        val noteTypeId: NoteTypeId? = null,
     ) : NoteEditorLauncher {
         override fun toBundle(): Bundle =
-            bundleOf(
+            bundleOfNotNull(
                 NoteEditorFragment.EXTRA_CALLER to NoteEditorCaller.NOTEEDITOR.value,
                 NoteEditorFragment.EXTRA_DID to deckId,
                 NoteEditorFragment.EXTRA_CONTENTS to fieldsText,
+                noteTypeId?.let { NoteEditorFragment.EXTRA_NOTE_TYPE_ID to it },
             ).also { bundle ->
                 tags?.let { tags -> bundle.putStringArray(NoteEditorFragment.EXTRA_TAGS, tags.toTypedArray()) }
             }

AnkiDroid/src/main/java/com/ichi2/anki/utils/ext/List.kt

@@ -0,0 +1,28 @@
+/*
+ *  Copyright (c) 2026 David Allison <[email protected]>
+ *
+ *  This program is free software; you can redistribute it and/or modify it under
+ *  the terms of the GNU General Public License as published by the Free Software
+ *  Foundation; either version 3 of the License, or (at your option) any later
+ *  version.
+ *
+ *  This program is distributed in the hope that it will be useful, but WITHOUT ANY
+ *  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ *  PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with
+ *  this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.ichi2.anki.utils.ext
+
+/**
+ * Returns the index of the first occurrence of the specified element in the list, or `null` if
+ * the specified element is not contained in the list.
+ *
+ * For lists containing more than [Int.MAX_VALUE] elements, a result of this function is unspecified.
+ */
+fun <T> List<T>.indexOfOrNull(value: T): Int? {
+    val index = indexOf(value)
+    return if (index >= 0) index else null
+}

AnkiDroid/src/test/java/com/ichi2/anki/NoteEditorTest.kt

@@ -255,6 +255,24 @@ class NoteEditorTest : RobolectricTest() {
         assertThat("Deck ID in the new note should be the ID provided in the intent", newNoteEditor.deckId, equalTo(currentDid))
     }
 
+    @Test
+    fun copyNoteCopiesNoteType() {
+        val originalNote = addBasicAndReversedNote()
+
+        // update the last selected note type so the test does not pass by accident
+        addBasicNote()
+
+        val editor = openNoteEditorWithArgs(NoteEditorLauncher.EditCard(originalNote.firstCard().id, DEFAULT).toBundle())
+        val copyNoteBundle = getCopyNoteIntent(editor)
+        val newNoteEditor = openNoteEditorWithArgs(copyNoteBundle)
+
+        assertThat(
+            "the note type of the copied note should be the same as the original",
+            newNoteEditor.editorNote!!.notetype.name,
+            equalTo(col.notetypes.basicAndReversed.name),
+        )
+    }
+
     @Test
     fun stickyFieldsAreUnchangedAfterAdd() =
         runTest {
@@ -282,6 +300,33 @@ class NoteEditorTest : RobolectricTest() {
             assertThat("newlines should be preserved, second field should be blanked", actual, contains(newFirstField, ""))
         }
 
+    @Test
+    fun `changing note type preserves and restores field contents`() =
+        runTest {
+            val threeFieldNoteTypeName = "ThreeFieldType"
+            val fieldNames = arrayOf("F1", "F2", "F3")
+            addStandardNoteType(threeFieldNoteTypeName, fieldNames, "{{F1}}", "{{F2}}")
+            val threeFieldNoteType = col.notetypes.byName(threeFieldNoteTypeName)!!
+            val basicNoteType = col.notetypes.basic
+
+            withNoteEditorAdding {
+                noteType = threeFieldNoteType
+                val originalTexts = fieldNames.map { "Text for $it" }
+                originalTexts.forEachIndexed { i, text -> fields[i] = text }
+
+                noteType = basicNoteType
+
+                assertThat("Field 1 should be copied", fields[0], equalTo(originalTexts[0]))
+                assertThat("Field 2 should be copied", fields[1], equalTo(originalTexts[1]))
+
+                noteType = threeFieldNoteType
+
+                originalTexts.forEachIndexed { i, text ->
+                    assertThat("Field ${i + 1} should be restored from memory", fields[i], equalTo(text))
+                }
+            }
+        }
+
     @Test
     fun `sticky fields do not impact current values`() =
         runTest {
@@ -792,9 +837,10 @@ class NoteEditorTest : RobolectricTest() {
         }
 
         fun buildInternal(): NoteEditorFragment {
-            col.notetypes.setCurrent(notetype)
             val noteEditor = getNoteEditorAddingNote(REVIEWER)
             advanceRobolectricLooper()
+            noteEditor.setCurrentlySelectedNoteType(notetype.id)
+            advanceRobolectricLooper()
             // image occlusion does not need a first field
             if (this.firstField != null) {
                 noteEditor.setFieldValueFromUi(0, firstField)