diff --git a/java/java-tests/testData/inspection/dataFlow/contractCheck/ConditionsConflict.java b/java/java-tests/testData/inspection/dataFlow/contractCheck/ConditionsConflict.java
index d22a85b86af0..9dc6e7674f72 100644
--- a/java/java-tests/testData/inspection/dataFlow/contractCheck/ConditionsConflict.java
+++ b/java/java-tests/testData/inspection/dataFlow/contractCheck/ConditionsConflict.java
@@ -8,7 +8,7 @@ class Foo {
   @Contract("!null -> !null; <warning descr="Contract clause '!null -> null' is never satisfied as its conditions are covered by previous contracts">!null -> null</warning>")
   public native String repeating(String x);
 
-  @Contract("true, false, _ -> !null; true, true, _\u0020-> null; <warning descr="Contract clause 'true, _, _ -> fail' is never satisfied as its conditions are covered by previous contracts">true, _, _ -> fail</warning>")
+  @Contract("true, false, _ ->\40!null; true, true,\040_\u0020-> null; <warning descr="Contract clause 'true, _, _ -> fail' is never satisfied as its conditions are covered by previous contracts">true, _, _ -> fail</warning>")
   public native String booleanProblem(boolean x, boolean y, String z);
 
   @Contract("true, false, _ -> !null; true, true, _ -> null; false, _, _ -> fail")
diff --git a/platform/core-impl/src/com/intellij/codeInsight/CodeInsightUtilCore.java b/platform/core-impl/src/com/intellij/codeInsight/CodeInsightUtilCore.java
index 09f03b90739a..47e4e08bc26c 100644
--- a/platform/core-impl/src/com/intellij/codeInsight/CodeInsightUtilCore.java
+++ b/platform/core-impl/src/com/intellij/codeInsight/CodeInsightUtilCore.java
@@ -18,6 +18,7 @@ package com.intellij.codeInsight;
 import com.intellij.lang.Language;
 import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.editor.RangeMarker;
+import com.intellij.openapi.util.TextRange;
 import com.intellij.psi.PsiDocumentManager;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
@@ -212,9 +213,71 @@ public abstract class CodeInsightUtilCore extends FileModificationService {
           }
       }
       if (sourceOffsets != null) {
-        sourceOffsets[outChars.length()-outOffset] = index;
+        sourceOffsets[outChars.length() - outOffset] = index;
       }
     }
     return true;
   }
+
+  /**
+   * Maps the substring range inside Java String literal value back into the source code range.
+   *
+   * @param text string literal as present in source code (including quotes)
+   * @param from start offset inside the represented string
+   * @param to end offset inside the represented string
+   * @return the range which represents the corresponding substring inside source representation,
+   * or null if from/to values are out of bounds.
+   */
+  @Nullable
+  public static TextRange mapBackStringRange(@NotNull String text, int from, int to) {
+    if (from > to || to < 0) return null;
+    if (text.startsWith("`")) {
+      // raw string
+      return new TextRange(from + 1, to + 1);
+    }
+    if (!text.startsWith("\"")) {
+      return null;
+    }
+    if (text.indexOf('\\') == -1) {
+      return new TextRange(from + 1, to + 1);
+    }
+    int curOffset = 0;
+    int mappedFrom = -1, mappedTo = -1;
+    int end = text.length() - 1;
+    int i = 1;
+    while (i <= end) {
+      if (curOffset == from) {
+        mappedFrom = i;
+      }
+      if (curOffset == to) {
+        mappedTo = i;
+        break;
+      }
+      if (i == end) break;
+      char c = text.charAt(i++);
+      if (c == '\\') {
+        if (i == end) return null;
+        // like \u0020
+        char c1 = text.charAt(i++);
+        if (c1 == 'u') {
+          while (i < end && text.charAt(i) == 'u') i++;
+          i += 4;
+        } else if (c1 >= '0' && c1 <= '7') { // octal escape
+          char c2 = i < end ? text.charAt(i) : 0;
+          if (c2 >= '0' && c2 <= '7') {
+            i++;
+            char c3 = i < end ? text.charAt(i) : 0;
+            if (c3 >= '0' && c3 <= '7' && c1 <= '3') {
+              i++;
+            }
+          }
+        }
+      }
+      curOffset++;
+    }
+    if (mappedFrom >= 0 && mappedTo >= 0) {
+      return new TextRange(mappedFrom, mappedTo);
+    }
+    return null;
+  }
 }
diff --git a/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ExpressionUtils.java b/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ExpressionUtils.java
index 5852ab154f6e..82e2186679c6 100644
--- a/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ExpressionUtils.java
+++ b/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/psiutils/ExpressionUtils.java
@@ -15,10 +15,7 @@
  */
 package com.siyeh.ig.psiutils;
 
-import com.intellij.codeInsight.AnnotationUtil;
-import com.intellij.codeInsight.ExpressionUtil;
-import com.intellij.codeInsight.NullableNotNullManager;
-import com.intellij.codeInsight.PsiEquivalenceUtil;
+import com.intellij.codeInsight.*;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.TextRange;
 import com.intellij.psi.*;
@@ -1258,43 +1255,7 @@ public class ExpressionUtils {
     if (expression instanceof PsiLiteralExpression) {
       String value = tryCast(((PsiLiteralExpression)expression).getValue(), String.class);
       if (value == null || value.length() < from || value.length() < to) return null;
-      String text = expression.getText();
-      if (text.startsWith("`")) {
-        // raw-string
-        return new TextRange(1 + from, 1 + to);
-      }
-      if (text.startsWith("\"")) {
-        int curOffset = 0;
-        int mappedFrom = -1, mappedTo = -1;
-        int end = text.length() - 1;
-        int i = 1;
-        while (i <= end) {
-          if (curOffset == from) {
-            mappedFrom = i;
-          }
-          if (curOffset == to) {
-            mappedTo = i;
-            break;
-          }
-          if (i == end) break;
-          char c = text.charAt(i);
-          if (c == '\\') {
-            i++;
-            if (i == end) return null;
-            // like \u0020
-            if (text.charAt(i) == 'u') {
-              while (i < end && text.charAt(i) == 'u') i++;
-              i += 3;
-            }
-          }
-          curOffset++;
-          i++;
-        }
-        if (mappedFrom >= 0 && mappedTo >= 0) {
-          return new TextRange(mappedFrom, mappedTo);
-        }
-      }
-      return null;
+      return CodeInsightUtilCore.mapBackStringRange(expression.getText(), from, to);
     }
     if (expression instanceof PsiParenthesizedExpression) {
       PsiExpression operand = ((PsiParenthesizedExpression)expression).getExpression();