Fix exception highlighting last CR in file

Custom implementation of offsetToCharacterPosition failed when the text range of the last CR in the file wrapped to a line that didn't exist in the editor. This caused an exception when search highlights included the last CR in the file

src/com/maddyhome/idea/vim/helper/EditorHelper.java

@@ -538,13 +538,12 @@ public class EditorHelper {
 
   @NotNull
   public static CharacterPosition offsetToCharacterPosition(@NotNull final Editor editor, final int offset) {
-    int line = editor.getDocument().getLineNumber(normalizeOffset(editor, offset));
-    int col = offset - editor.getDocument().getLineStartOffset(line);
-    return new CharacterPosition(line, col);
+    final LogicalPosition logicalPosition = editor.offsetToLogicalPosition(offset);
+    return new CharacterPosition(logicalPosition.line, logicalPosition.column);
   }
 
   public static int characterPositionToOffset(@NotNull final Editor editor, @NotNull final CharacterPosition pos) {
-    return editor.getDocument().getLineStartOffset(normalizeLine(editor, pos.line)) + pos.column;
+    return editor.logicalPositionToOffset(pos);
   }
 
   @NotNull

test/org/jetbrains/plugins/ideavim/group/SearchGroupTest.kt

@@ -22,10 +22,12 @@ import com.intellij.openapi.util.Ref
 import com.intellij.testFramework.UsefulTestCase
 import com.maddyhome.idea.vim.VimPlugin
 import com.maddyhome.idea.vim.command.CommandFlags
+import com.maddyhome.idea.vim.group.SearchGroup
 import com.maddyhome.idea.vim.helper.RunnableHelper
 import com.maddyhome.idea.vim.helper.StringHelper.parseKeys
 import com.maddyhome.idea.vim.option.Options
 import com.maddyhome.idea.vim.option.ToggleOption
+import junit.framework.TestCase
 import org.jetbrains.plugins.ideavim.VimTestCase
 import java.util.*
 
@@ -226,21 +228,18 @@ class SearchGroupTest : VimTestCase() {
     }
 
     fun `test search word matches case`() {
-        resetAllOptions()
         typeTextInFile(parseKeys("*"),
             "<caret>Editor editor Editor")
         assertOffset(14)
     }
 
     fun `test search next word matches case`() {
-        resetAllOptions()
         typeTextInFile(parseKeys("*", "n"),
             "<caret>Editor editor Editor editor Editor")
         assertOffset(28)
     }
 
     fun `test search word honours ignorecase`() {
-        resetAllOptions()
         setIgnoreCase()
         typeTextInFile(parseKeys("*"),
             "<caret>editor Editor editor")
@@ -248,7 +247,6 @@ class SearchGroupTest : VimTestCase() {
     }
 
     fun `test search next word honours ignorecase`() {
-        resetAllOptions()
         setIgnoreCase()
         typeTextInFile(parseKeys("*", "n"),
             "<caret>editor Editor editor")
@@ -256,7 +254,6 @@ class SearchGroupTest : VimTestCase() {
     }
 
     fun `test search word overrides smartcase`() {
-        resetAllOptions()
         setIgnoreCaseAndSmartCase()
         typeTextInFile(parseKeys("*"),
             "<caret>Editor editor Editor")
@@ -264,16 +261,20 @@ class SearchGroupTest : VimTestCase() {
     }
 
     fun `test search next word overrides smartcase`() {
-        resetAllOptions()
         setIgnoreCaseAndSmartCase()
         typeTextInFile(parseKeys("*", "n"),
             "<caret>Editor editor editor")
         assertOffset(14)
     }
 
-    private fun resetAllOptions() {
-        val options = Options.getInstance()
-        options.resetAllOptions()
+    // Ensure that the offsets for the last carriage return in the file are valid, even though it's for a line that
+    // doesn't exist
+    fun `test find last cr in file`() {
+        myFixture.configureByText("a.txt", "Something\n")
+        val textRange = SearchGroup.findNext(myFixture.editor, "\\n", 0, false, true)
+        assertNotNull(textRange)
+        TestCase.assertEquals(9, textRange?.startOffset)
+        TestCase.assertEquals(10, textRange?.endOffset)
     }
 
     private fun setIgnoreCase() {