From f5aa2eb74982a5cc61fbda940c00644bdd5a31d9 Mon Sep 17 00:00:00 2001
From: Katarzyna Marek <kasia@marek.net>
Date: Wed, 13 Sep 2023 18:57:40 +0200
Subject: [PATCH] bugfix: handle EOF in java completions

---
 .../scala/meta/internal/pc/JavaCompletionProvider.scala  | 4 +++-
 .../scala/meta/internal/mtags/JavaToplevelMtags.scala    | 2 +-
 .../src/test/scala/pc/CompletionKeywordSuite.scala       | 9 +++++++++
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/mtags-java/src/main/scala/scala/meta/internal/pc/JavaCompletionProvider.scala b/mtags-java/src/main/scala/scala/meta/internal/pc/JavaCompletionProvider.scala
index 326c3de1ec4..b1fe39e9382 100644
--- a/mtags-java/src/main/scala/scala/meta/internal/pc/JavaCompletionProvider.scala
+++ b/mtags-java/src/main/scala/scala/meta/internal/pc/JavaCompletionProvider.scala
@@ -36,7 +36,9 @@ class JavaCompletionProvider(
   lazy val identifier = extractIdentifier.toLowerCase
   def completions(): CompletionList = {
     val nextIsWhitespace =
-      params.text().charAt(params.offset()).isWhitespace
+      if (params.offset() < params.text().length())
+        params.text().charAt(params.offset()).isWhitespace
+      else false
     val textWithSemicolon =
       if (nextIsWhitespace)
         params.text().substring(0, params.offset()) +
diff --git a/mtags/src/main/scala/scala/meta/internal/mtags/JavaToplevelMtags.scala b/mtags/src/main/scala/scala/meta/internal/mtags/JavaToplevelMtags.scala
index 8a5bf0550e4..80fee852cfb 100644
--- a/mtags/src/main/scala/scala/meta/internal/mtags/JavaToplevelMtags.scala
+++ b/mtags/src/main/scala/scala/meta/internal/mtags/JavaToplevelMtags.scala
@@ -80,7 +80,7 @@ class JavaToplevelMtags(val input: Input.VirtualFile) extends MtagsIndexer {
     @tailrec
     def kwOrIdent(start: Int, builder: StringBuilder): Token = {
       val ch = reader.ch
-      if (Character.isJavaIdentifierPart(ch)) {
+      if (ch != SU && Character.isJavaIdentifierPart(ch)) {
         reader.nextChar()
         kwOrIdent(start, builder.append(ch))
       } else if (builder.isEmpty) {
diff --git a/tests/javapc/src/test/scala/pc/CompletionKeywordSuite.scala b/tests/javapc/src/test/scala/pc/CompletionKeywordSuite.scala
index fb1ea5686cc..820a7a85ffa 100644
--- a/tests/javapc/src/test/scala/pc/CompletionKeywordSuite.scala
+++ b/tests/javapc/src/test/scala/pc/CompletionKeywordSuite.scala
@@ -53,6 +53,15 @@ class CompletionKeywordSuite extends BaseJavaCompletionSuite {
       |""".stripMargin,
   )
 
+  check(
+    "end of file",
+    """
+      |pac@@""".stripMargin,
+    """
+      |package
+      |""".stripMargin,
+  )
+
   check(
     "extends",
     """