Return exit code 1 in case violations have been found but file is unc…

…hanged (#2803)

In very rare cases it is possible that Lint violations are detected while formatting but that they have opposite effects and the file gets not altered at all. As the logging already might contain the message "Format was not able to resolve all violations which (theoretically) can be autocorrected in file ..." the format may not return with exit code 0.

Closes #2795

ktlint-cli/src/main/kotlin/com/pinterest/ktlint/cli/internal/KtlintCommandLine.kt

@@ -508,6 +508,11 @@ internal class KtlintCommandLine :
                             }
                         } ?: NO_AUTOCORRECT
                 }.also { formattedFileContent ->
+                    if (ktlintCliErrors.isNotEmpty() && code.content == formattedFileContent) {
+                        // In very rare cases it is possible that Lint violations are detected but that they have opposite effects and the
+                        // file gets not altered at all. This is to be treated as unfixable error.
+                        containsUnfixedLintErrors.set(true)
+                    }
                     if (forceLintAfterFormat && code.content != formattedFileContent) {
                         // Rerun lint to check that the formatted code can still be successfully parsed.
                         try {
@@ -721,7 +726,7 @@ internal class KtlintCommandLine :
                         q.put(executorService.submit(task))
                     }
                     q.put(pill)
-                } catch (e: InterruptedException) {
+                } catch (_: InterruptedException) {
                     // we've been asked to stop consuming sequence
                 } finally {
                     executorService.shutdown()