Fix C++ and Hash styles with headerEmptyLine := false

src/main/scala/de/heikoseeberger/sbtheader/HeaderPlugin.scala

@@ -56,7 +56,7 @@ object HeaderPlugin extends AutoPlugin {
         raw"""(?s)($start(?!\$middle).*?$end(?:\n|\r|\r\n)+)(.*)""".r
 
       def commentStartingWith(start: String): Regex =
-        raw"""(?s)((?:$start[^\n\r]*(?:\n|\r|\r\n))*(?:$start[^\n\r]*(?:(?:\n){2,}|(?:\r){2,}|(?:\r\n){2,})+))(.*)""".r
+        raw"""(?s)((?:$start[^\n\r]*(?:\n|\r|\r\n))*(?:$start[^\n\r]*(?:(?:\n)+|(?:\r)+|(?:\r\n)+)+))(.*)""".r
     }
 
     val HeaderFileType = FileType

src/test/scala/de/heikoseeberger/sbtheader/CommentStyleSpec.scala

@@ -119,11 +119,10 @@ class CommentStyleSpec extends AnyWordSpec with Matchers {
     }
 
     "not match a multiline block comment with a single trailing new line" in {
-      cppStyleLineComment.pattern.unapplySeq(
-        """|// comment/1
-           |// comment/2
-           |""".stripMargin
-      ) shouldBe None
+      val header = """|// comment/1
+                      |// comment/2
+                      |""".stripMargin
+      cppStyleLineComment.pattern.unapplySeq(header) shouldBe Some(List(header, ""))
     }
 
     "match a comment with trailing new lines not followed by a body" in {
@@ -161,12 +160,11 @@ class CommentStyleSpec extends AnyWordSpec with Matchers {
       hashLineComment.pattern.unapplySeq("# comment") shouldBe None
     }
 
-    "not match a multiline block comment with a single trailing new line" in {
-      hashLineComment.pattern.unapplySeq(
-        """|# comment/1
-           |# comment/2
-           |""".stripMargin
-      ) shouldBe None
+    "match a multiline block comment with a single trailing new line" in {
+      val header = """|# comment/1
+                      |# comment/2
+                      |""".stripMargin
+      hashLineComment.pattern.unapplySeq(header) shouldBe Some(List(header, ""))
     }
 
     "match a comment with trailing new lines not followed by a body" in {

src/test/scala/de/heikoseeberger/sbtheader/HeaderCreatorSpec.scala

@@ -221,7 +221,7 @@ final class HeaderCreatorSpec extends AnyWordSpec with Matchers {
     }
 
     "given a file without an empty line between the header and the body" should {
-      "preserve the file without the empty line" in {
+      "preserve the file with C style without the empty line" in {
         val fileContent = """/*
           | * Copyright 2017 MyCorp, Inc <https://mycorp.com>
           | */
@@ -235,6 +235,34 @@ final class HeaderCreatorSpec extends AnyWordSpec with Matchers {
           headerEmptyLine = false
         ) shouldBe None
       }
+
+      "preserve the file with C++ style without the empty line" in {
+        val fileContent =
+          """// Copyright 2017 MyCorp, Inc <https://mycorp.com>
+            |This is the file content
+            |""".stripMargin
+
+        createHeader(
+          fileContent = fileContent,
+          header = "Copyright 2017 MyCorp, Inc <https://mycorp.com>",
+          commentCreator = CommentStyle.cppStyleLineComment,
+          headerEmptyLine = false
+        ) shouldBe None
+      }
+
+      "preserve the file with hash style without the empty line" in {
+        val fileContent =
+          """# Copyright 2017 MyCorp, Inc <https://mycorp.com>
+            |This is the file content
+            |""".stripMargin
+
+        createHeader(
+          fileContent = fileContent,
+          header = "Copyright 2017 MyCorp, Inc <https://mycorp.com>",
+          commentCreator = CommentStyle.hashLineComment,
+          headerEmptyLine = false
+        ) shouldBe None
+      }
     }
   }