Fix KT-8091: J2K string with octal escaped chars

j2k/src/org/jetbrains/kotlin/j2k/ExpressionConverter.kt

@@ -314,6 +314,9 @@ class DefaultExpressionConverter : JavaElementVisitor(), ExpressionConverter {
             }
 
             if (typeStr == "java.lang.String") {
+                text = text.replace("\\\\([0-3]?[0-7]{1,2})".toRegex(), {
+                    String.format("\\u%04x", Integer.parseInt(it.groupValues[1], 8))
+                })
                 text = text.replace("\\$([A-Za-z]+|\\{)".toRegex(), "\\\\$0")
             }
         }

j2k/testData/fileOrElement/literalExpression/stringOctalChars.java

@@ -0,0 +1,7 @@
+public class A {
+    public String a = "\770123";
+    public String b = "\1110123";
+    public String c = "\3770123";
+    public String d = "\000Text";
+    public String f = "\09";
+}

j2k/testData/fileOrElement/literalExpression/stringOctalChars.kt

@@ -0,0 +1,7 @@
+class A {
+    var a = "\u003f0123"
+    var b = "\u00490123"
+    var c = "\u00ff0123"
+    var d = "\u0000Text"
+    var f = "\u00009"
+}

j2k/tests/org/jetbrains/kotlin/j2k/JavaToKotlinConverterForWebDemoTestGenerated.java

@@ -3232,6 +3232,12 @@ public class JavaToKotlinConverterForWebDemoTestGenerated extends AbstractJavaTo
             doTest(fileName);
         }
 
+        @TestMetadata("stringOctalChars.java")
+        public void testStringOctalChars() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("j2k/testData/fileOrElement/literalExpression/stringOctalChars.java");
+            doTest(fileName);
+        }
+
         @TestMetadata("trueOrFalse.java")
         public void testTrueOrFalse() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("j2k/testData/fileOrElement/literalExpression/trueOrFalse.java");

j2k/tests/org/jetbrains/kotlin/j2k/JavaToKotlinConverterSingleFileTestGenerated.java

@@ -3232,6 +3232,12 @@ public class JavaToKotlinConverterSingleFileTestGenerated extends AbstractJavaTo
             doTest(fileName);
         }
 
+        @TestMetadata("stringOctalChars.java")
+        public void testStringOctalChars() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("j2k/testData/fileOrElement/literalExpression/stringOctalChars.java");
+            doTest(fileName);
+        }
+
         @TestMetadata("trueOrFalse.java")
         public void testTrueOrFalse() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("j2k/testData/fileOrElement/literalExpression/trueOrFalse.java");