Fix NPE if or operator at start of line followed by dot qualified expression

CHANGELOG.md

@@ -13,6 +13,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 * Print absolute path of file in lint violations when flag "--relative" is not specified in Ktlint CLI ([#1963](https://github.com/pinterest/ktlint/issues/1963)) 
 * Handle parameter `--code-style=android_studio` in Ktlint CLI identical to deprecated parameter `--android` ([#1982](https://github.com/pinterest/ktlint/issues/1982))
 * Prevent nullpointer exception (NPE) if class without body is followed by multiple blank lines until end of file `no-consecutive-blank-lines` ([#1987](https://github.com/pinterest/ktlint/issues/1987))
+* Prevent nullpointer exception (NPE) if or operator at start of line is followed by dot qualified expression `indent` ([#1993](https://github.com/pinterest/ktlint/issues/1993))
 
 ### Changed
 * Separated Baseline functionality out of `ktlint-cli` into separate `ktlint-baseline` module for API consumers

ktlint-ruleset-standard/src/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/IndentationRule.kt

@@ -1091,7 +1091,7 @@ public class IndentationRule :
  private fun ASTNode?.isElvisOperator() =
  this != null &&
  elementType == OPERATION_REFERENCE &&
- firstChildNode.elementType == ELVIS
+ firstChildNode?.elementType == ELVIS
 
  private fun ASTNode.acceptableTrailingSpaces(): String {
  require(elementType == WHITE_SPACE)

ktlint-ruleset-standard/src/test/kotlin/com/pinterest/ktlint/ruleset/standard/rules/IndentationRuleTest.kt

@@ -5122,6 +5122,32 @@ internal class IndentationRuleTest {
  }
  }
 
+ @Test
+ fun `Issue 1993 - An or operator at start of line followed by a dot qualified expressions should not throw an exception`() {
+ val code =
+ """
+ val foo =
+ if (false
+ || foobar.bar()
+ ) {
+ // Do something
+ }
+ """.trimIndent()
+ val formattedCode =
+ """
+ val foo =
+ if (false ||
+ foobar.bar()
+ ) {
+ // Do something
+ }
+ """.trimIndent()
+ indentationRuleAssertThat(code)
+ .addAdditionalRuleProvider { ChainWrappingRule() }
+ .hasLintViolationForAdditionalRule(3, 9, "Line must not begin with \"||\"")
+ .isFormattedAs(formattedCode)
+ }
+
  private companion object {
  val INDENT_STYLE_TAB =
  INDENT_STYLE_PROPERTY to PropertyType.IndentStyleValue.tab