#807 JsonPointer double slashes validation

Author: Piotr Bugara

src/main/java/com/github/fge/jsonpatch/JsonPathParser.java

@@ -7,9 +7,10 @@ public class JsonPathParser {
     public static String tmfStringToJsonPath(String path) throws JsonPatchException {
         if (path.startsWith("$")) {
             return path;
-        }
-        if (path.contains("?")) {
+        } else if (path.contains("?")) {
             throw new JsonPatchException("Invalid path, `?` are not allowed in JsonPointer expressions.");
+        } else if (path.contains("//")) {
+            throw new JsonPatchException("Invalid path, `//` is not allowed in JsonPointer expressions.");
         }
 
         return "$" + path.replace('/', '.').replaceAll(ARRAY_ELEMENT_REGEX, "[$1]");

src/test/java/com/github/fge/jsonpatch/JsonPathParserTest.java

@@ -2,6 +2,7 @@
 
 import org.testng.annotations.Test;
 
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.testng.Assert.*;
 
 public class JsonPathParserTest {
@@ -45,4 +46,10 @@ public void shouldLeaveJsonPathStatementsUntouched() throws JsonPatchException {
         String result = JsonPathParser.tmfStringToJsonPath(filterQuery);
         assertEquals(result, expected);
     }
+
+    @Test(expectedExceptions = JsonPatchException.class, expectedExceptionsMessageRegExp = "Invalid path, `//` is not allowed in JsonPointer expressions.")
+    public void shouldThrowExceptionWhenDoubleSlashesInJsonPointerPath() throws JsonPatchException {
+        String filterQuery = "/characteristic/0//age";
+        JsonPathParser.tmfStringToJsonPath(filterQuery);
+    }
 }