Adding feature to allow for skipping RS control char #633

src/main/java/com/fasterxml/jackson/core/JsonParser.java

@@ -138,6 +138,20 @@ public enum Feature {
          */
         ALLOW_SINGLE_QUOTES(false),
 
+        /**
+         * Feature that determines whether parser will allow use 
+         * of the RS control character (exhibited by 0x1E and parsed as a
+         * tab or /t) within parsed content or not. 
+         *<p>
+         * Since JSON specification requires use of double quotes for
+         * field names,
+         * this is a non-standard feature, and as such disabled by default.
+         *<p>
+         * NOTE: while not technically deprecated, since 2.10 recommended to use
+         * {@link com.fasterxml.jackson.core.json.JsonReadFeature#ALLOW_SINGLE_QUOTES} instead.
+         */
+        ALLOW_RS_CONTROL_CHAR(false),
+
         /**
          * Feature that determines whether parser will allow
          * JSON Strings to contain unquoted control characters

src/main/java/com/fasterxml/jackson/core/base/ParserMinimalBase.java

@@ -29,6 +29,7 @@ public abstract class ParserMinimalBase extends JsonParser
     protected final static int INT_LF = '\n';
     protected final static int INT_CR = '\r';
     protected final static int INT_SPACE = 0x0020;
+    protected final static int INT_RS = 0x001E;
 
     // Markup
     protected final static int INT_LBRACKET = '[';

src/main/java/com/fasterxml/jackson/core/json/JsonReadFeature.java

@@ -11,6 +11,21 @@
 public enum JsonReadFeature
     implements FormatFeature
 {
+    // // // Support for non-standard data format constructs: whitespaces
+
+    /**
+     * Feature that determines whether parser will allow use 
+     * of the RS control character (exhibited by 0x1E and parsed as a
+     * tab or /t) within parsed content or not. 
+     *<p>
+     * Since JSON specification does not mention comments as legal
+     * construct,
+     * this is a non-standard feature. As such, feature is
+     * <b>disabled by default</b> for parsers and must be
+     * explicitly enabled.
+     */
+    ALLOW_RS_CONTROL_CHAR(false, JsonParser.Feature.ALLOW_RS_CONTROL_CHAR),
+
     // // // Support for non-standard data format constructs: comments
 
     /**

src/main/java/com/fasterxml/jackson/core/json/ReaderBasedJsonParser.java

@@ -35,6 +35,8 @@ public class ReaderBasedJsonParser
 
     private final static int FEAT_MASK_ALLOW_JAVA_COMMENTS = Feature.ALLOW_COMMENTS.getMask();
     private final static int FEAT_MASK_ALLOW_YAML_COMMENTS = Feature.ALLOW_YAML_COMMENTS.getMask();
+
+    private final static int FEAT_MASK_ALLOW_CONTROL_CHAR = Feature.ALLOW_RS_CONTROL_CHAR.getMask();
 
     // Latin1 encoding is not supported, but we do use 8-bit subset for
     // pre-processing task, to simplify first pass, keep it fast.
@@ -2538,8 +2540,8 @@ private final int _skipWSOrEnd() throws IOException
                 _currInputRowStart = _inputPtr;
             } else if (i == INT_CR) {
                 _skipCR();
-            } else if (i != INT_TAB) {
-                _throwInvalidSpace(i);
+            } else if (i != INT_TAB && ((_features & FEAT_MASK_ALLOW_CONTROL_CHAR) != 0 && i != INT_RS)) {
+                    _throwInvalidSpace(i);
             }
         }
 
@@ -2558,7 +2560,7 @@ private final int _skipWSOrEnd() throws IOException
                     _currInputRowStart = _inputPtr;
                 } else if (i == INT_CR) {
                     _skipCR();
-                } else if (i != INT_TAB) {
+                } else if (i != INT_TAB && ((_features & FEAT_MASK_ALLOW_CONTROL_CHAR) != 0 && i != INT_RS)) {
                     _throwInvalidSpace(i);
                 }
             }

src/test/java/com/fasterxml/jackson/core/json/async/AsyncNonStdParsingTest.java

@@ -387,4 +387,5 @@ private AsyncReaderWrapper createParser(JsonFactory f, String doc,
     {
         return asyncForBytes(f, readSize, _jsonDoc(doc), offset);
     }
+
 }