From e6e401fbe1f883ed337a1c8ac4a6c99c3ed7b872 Mon Sep 17 00:00:00 2001
From: Bas Leijdekkers <bas.leijdekkers@jetbrains.com>
Date: Fri, 13 Jun 2025 16:56:13 +0200
Subject: [PATCH] Java: don't produce NUL characters in Convert to Markdown
 documentation output (IDEA-374488)

GitOrigin-RevId: b96d7cc559b0ffbc5130131961b8a530b9baba9c
---
 .../MarkdownDocumentationCommentsMigrationInspection.java | 2 +-
 .../MarkdownDocumentationCommentsMigration.after.java     | 6 +++++-
 .../MarkdownDocumentationCommentsMigration.java           | 8 +++++++-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/java/java-analysis-impl/src/com/siyeh/ig/migration/MarkdownDocumentationCommentsMigrationInspection.java b/java/java-analysis-impl/src/com/siyeh/ig/migration/MarkdownDocumentationCommentsMigrationInspection.java
index 0c2a3ed4b5c4..3ee2067f7b55 100644
--- a/java/java-analysis-impl/src/com/siyeh/ig/migration/MarkdownDocumentationCommentsMigrationInspection.java
+++ b/java/java-analysis-impl/src/com/siyeh/ig/migration/MarkdownDocumentationCommentsMigrationInspection.java
@@ -205,7 +205,7 @@ public final class MarkdownDocumentationCommentsMigrationInspection extends Base
         else {
           if (context == Context.PRE) {
             if (c == '<' && match(html, "</pre>", i)) tag = i;
-            else result.append(c);
+            else if (c != '\u0000') result.append(c);
           }
           else if (c == '\u0000') { // NUL marks part where text should be taken raw
             int end = html.indexOf('\u0000', i + 1);
diff --git a/java/java-tests/testData/ig/com/siyeh/igtest/migration/markdown_documentation_comments_migration/MarkdownDocumentationCommentsMigration.after.java b/java/java-tests/testData/ig/com/siyeh/igtest/migration/markdown_documentation_comments_migration/MarkdownDocumentationCommentsMigration.after.java
index 34674eee7ae6..93e032677c22 100644
--- a/java/java-tests/testData/ig/com/siyeh/igtest/migration/markdown_documentation_comments_migration/MarkdownDocumentationCommentsMigration.after.java
+++ b/java/java-tests/testData/ig/com/siyeh/igtest/migration/markdown_documentation_comments_migration/MarkdownDocumentationCommentsMigration.after.java
@@ -383,4 +383,8 @@ interface Foo<T, B, P, I>
 ///
 /// </Pre>
 /// end
-class Preformatted {}
+class Preformatted {
+
+  /// <pre>`x`</pre>
+  protected void beginParsing() {}
+}
diff --git a/java/java-tests/testData/ig/com/siyeh/igtest/migration/markdown_documentation_comments_migration/MarkdownDocumentationCommentsMigration.java b/java/java-tests/testData/ig/com/siyeh/igtest/migration/markdown_documentation_comments_migration/MarkdownDocumentationCommentsMigration.java
index cdfe79fa2359..7d34b9f6d152 100644
--- a/java/java-tests/testData/ig/com/siyeh/igtest/migration/markdown_documentation_comments_migration/MarkdownDocumentationCommentsMigration.java
+++ b/java/java-tests/testData/ig/com/siyeh/igtest/migration/markdown_documentation_comments_migration/MarkdownDocumentationCommentsMigration.java
@@ -408,4 +408,10 @@ interface Foo<T, B, P, I>
  * </Pre>
  * end
  */
-class Preformatted {}
+class Preformatted {
+
+  <warning descr="Javadoc comment can be Markdown documentation comment">/**</warning>
+   * <pre>{@code x}</pre>
+   */
+  protected void beginParsing() {}
+}