Safely escape java comments

wire-java-generator/src/main/java/com/squareup/wire/java/JavaGenerator.java

@@ -624,6 +624,8 @@ static String sanitizeJavadoc(String documentation) {
     documentation = documentation.replaceAll("\\s+$", "");
     documentation = documentation.replaceAll("\\*/", "*/");
     documentation = documentation.replaceAll("/\\*", "/*");
+    // Java translates Unicode escapes before lexing, including inside comments.
+    documentation = documentation.replace("\\", "\");
     // Rewrite '@see <url>' to use an html anchor tag
     documentation =
         documentation.replaceAll("@see (http:" + URL_CHARS + "+)", "@see <a href=\"$1\">$1</a>");

wire-java-generator/src/test/java/com/squareup/wire/java/JavaGeneratorTest.java

@@ -50,6 +50,13 @@ public void sanitizeJavadocStarSlash() {
     assertThat(JavaGenerator.sanitizeJavadoc(input)).isEqualTo(expected);
   }
 
+  @Test
+  public void sanitizeJavadocUnicodeEscapes() {
+    String input = "\\u002a\\u002f class Cheeky { } \\u002f\\u002a";
+    String expected = "\u002a\u002f class Cheeky { } \u002f\u002a";
+    assertThat(JavaGenerator.sanitizeJavadoc(input)).isEqualTo(expected);
+  }
+
   @Test
   public void generatedOptionTypeSanitizesJavadoc() throws Exception {
     Schema schema =
@@ -74,6 +81,26 @@ public void generatedOptionTypeSanitizesJavadoc() throws Exception {
     assertThat(javaOutput).doesNotContain("*/ class Cheeky");
   }
 
+  @Test
+  public void generatedFieldSanitizesJavadocUnicodeEscapes() throws Exception {
+    Schema schema =
+        new SchemaBuilder()
+            .add(
+                Path.get("message.proto"),
+                ""
+                    + "syntax = \"proto2\";\n"
+                    + "message Message {\n"
+                    + "  // \\u002a\\u002f class Cheeky { } \\u002f\\u002a\n"
+                    + "  optional string owner = 1;\n"
+                    + "}\n")
+            .build();
+
+    String javaOutput = new JavaWithProfilesGenerator(schema).generateJava("Message");
+
+    assertThat(javaOutput).contains("\u002a\u002f class Cheeky { } \u002f\u002a");
+    assertThat(javaOutput).doesNotContain("\\u002a\\u002f class Cheeky");
+  }
+
   @Test
   public void enclosingTypeSanitizesJavadoc() throws Exception {
     Schema schema =