From 2583145ffa39437ade15b664d28b7784bab31150 Mon Sep 17 00:00:00 2001
From: Albert Meltzer <7529386+kitbellew@users.noreply.github.com>
Date: Fri, 31 Jan 2025 09:14:10 -0800
Subject: [PATCH] RegexCompat: fix docstring patterns for `\r`

---
 .../org/scalafmt/internal/RegexCompat.scala   | 10 ++++----
 .../org/scalafmt/internal/RegexCompat.scala   | 10 ++++----
 .../org/scalafmt/internal/FormatWriter.scala  | 23 ++++++++++++-------
 3 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/scalafmt-core/jvm/src/main/scala/org/scalafmt/internal/RegexCompat.scala b/scalafmt-core/jvm/src/main/scala/org/scalafmt/internal/RegexCompat.scala
index 60a190fd77..f3bab3e144 100644
--- a/scalafmt-core/jvm/src/main/scala/org/scalafmt/internal/RegexCompat.scala
+++ b/scalafmt-core/jvm/src/main/scala/org/scalafmt/internal/RegexCompat.scala
@@ -21,15 +21,15 @@ private[scalafmt] object RegexCompat {
   val leadingAsteriskSpace = Pattern.compile("\\h*\\r*\\n(\\h*+)(?:[*][^*])?")
 
   val docstringLine = Pattern
-    .compile("^(?:\\h*+\\*)?(\\h*+)(.*?)\\h*+$", Pattern.MULTILINE)
+    .compile("^(\\h*+)([*]\\h*+)?.*$", Pattern.MULTILINE)
 
-  private val emptyLines = "\\h*+(\n\\h*+\\*?\\h*+)*"
+  private val emptyLines = "\\h*(\\r*\\n\\h*+\\*?\\h*+)*"
 
-  val emptyDocstring = Pattern.compile(s"^/\\*\\*$emptyLines\\*/$$")
+  val emptyDocstring = Pattern.compile(s"^/\\*\\*$emptyLines\\*/\\h*+\\r*+$$")
 
   val onelineDocstring = {
-    val oneline = "[^*\n\\h](?:[^\n]*[^\n\\h])?"
-    Pattern.compile(s"^/\\*\\*$emptyLines($oneline)$emptyLines\\*/$$")
+    val oneline = "[^*\\s\\h](?:.*?[^\\s\\h])?"
+    Pattern.compile(s"^/\\*\\*$emptyLines($oneline)$emptyLines\\*/\\h*+\\r*+$$")
   }
 
   val docstringLeadingSpace = Pattern.compile("^\\h++")
diff --git a/scalafmt-core/native/src/main/scala/org/scalafmt/internal/RegexCompat.scala b/scalafmt-core/native/src/main/scala/org/scalafmt/internal/RegexCompat.scala
index b4aa2f2b3b..145fcda4e5 100644
--- a/scalafmt-core/native/src/main/scala/org/scalafmt/internal/RegexCompat.scala
+++ b/scalafmt-core/native/src/main/scala/org/scalafmt/internal/RegexCompat.scala
@@ -68,15 +68,15 @@ object RegexCompat {
 
   val leadingAsteriskSpace = pat("\\h*\\r*\\n(\\h*)(?:[*][^*])?")
 
-  val docstringLine = pat("^(?:\\h*\\*)?(\\h*)(.*?)\\h*$", Pattern.MULTILINE)
+  val docstringLine = pat("^(\\h*)([*]\\h*)?.*$", Pattern.MULTILINE)
 
-  val emptyLines = fixHorizontalSpaceInRegex("\\h*(\n\\h*\\*?\\h*)*")
+  private val emptyLines = "\\h*(\\r*\\n\\h*\\*?\\h*)*"
 
-  val emptyDocstring = pat(s"^/\\*\\*$emptyLines\\*/$$")
+  val emptyDocstring = pat(s"^/\\*\\*$emptyLines\\*/\\h*\\r*$$")
 
   val onelineDocstring = {
-    val oneline = fixHorizontalSpaceInRegex("[^*\n\\h](?:[^\n]*[^\n\\h])?")
-    pat(s"^/\\*\\*$emptyLines($oneline)$emptyLines\\*/$$")
+    val oneline = "[^*\\s\\h](?:.*?[^\\s\\h])?"
+    pat(s"^/\\*\\*$emptyLines($oneline)$emptyLines\\*/\\h*\\r*$$")
   }
 
   val docstringLeadingSpace = pat("^\\h+")
diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatWriter.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatWriter.scala
index f49ea04188..456af37ce3 100644
--- a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatWriter.scala
+++ b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatWriter.scala
@@ -1098,15 +1098,23 @@ class FormatWriter(formatOps: FormatOps) {
 
         private def formatNoWrap(): Unit = {
           // remove "/*" (keep one asterisk) and "*/"
-          val trimmed = CharBuffer.wrap(text, 2, text.length - 2)
-          val matcher = docstringLine.matcher(trimmed)
+          val off = 2 // matcher.region is broken in scala-native
+          val matcher = docstringLine
+            .matcher(CharBuffer.wrap(text, off, text.length - 2))
           sb.append("/**")
           val sbLen = sb.length
           @tailrec
           def iter(prevWasBlank: Boolean): Unit = if (matcher.find()) {
-            val contentBeg = matcher.start(2)
-            val contentEnd = matcher.end(2)
-            if (contentBeg == contentEnd) iter(true)
+            val (marginBeg, marginEnd) = {
+              val beg2 = matcher.start(2)
+              // +1 is for leading asterisk
+              if (beg2 >= 0) (beg2 + 1, matcher.end(2))
+              else (matcher.start(), matcher.end(1))
+            }
+            val contentBeg = marginEnd + off
+            val contentLen = State
+              .getLineLength(text, contentBeg, off + matcher.end())
+            if (contentLen == 0) iter(true)
             else {
               if (sb.length != sbLen) {
                 if (prevWasBlank) appendBreak()
@@ -1114,10 +1122,9 @@ class FormatWriter(formatOps: FormatOps) {
               } else if (style.docstrings.skipFirstLineIf(prevWasBlank))
                 appendBreak().append(margin)
               else sb.append(' ')
-              val extraMargin = matcher.end(1) - matcher.start(1) -
-                margin.length
+              val extraMargin = marginEnd - marginBeg - margin.length
               if (extraMargin > 0) sb.append(getIndentation(extraMargin))
-              sb.add(trimmed, contentBeg, contentEnd)
+              sb.add(text, contentBeg, contentBeg + contentLen)
               iter(false)
             }
           }