Partial fix for #609 for 2.10(.4)

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -211,3 +211,8 @@ Scott Leberknight (sleberknight@github)
   * Reported, contributed fix for #592: DataFormatMatcher#getMatchedFormatName throws NPE
     when no match exists
   (2.10.3)
+
+Volkan Yazıcı (vy@github)
+  * Reported #609: (partial fix) `FilteringGeneratorDelegate` does not handle
+    `writeString(Reader, int)`
+  (2.10.4 [partial], 2.11.0 [full fix])

release-notes/VERSION-2.x

@@ -18,6 +18,8 @@ JSON library.
 
 #605: Handle case when system property access is restricted
  (reported by rhernandez35@github)
+#609: (partial fix) `FilteringGeneratorDelegate` does not handle `writeString(Reader, int)`
+ (reported by Volkan Y)
 
 2.10.3 (03-Mar-2020)
 

src/main/java/com/fasterxml/jackson/core/filter/FilteringGeneratorDelegate.java

@@ -2,6 +2,7 @@
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.Reader;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 
@@ -486,6 +487,30 @@ public void writeString(SerializableString value) throws IOException
         delegate.writeString(value);
     }
 
+    @Override
+    public void writeString(Reader reader, int len) throws IOException {
+        if (_itemFilter == null) {
+            return;
+        }
+        if (_itemFilter != TokenFilter.INCLUDE_ALL) {
+            TokenFilter state = _filterContext.checkValue(_itemFilter);
+            if (state == null) {
+                return;
+            }
+            if (state != TokenFilter.INCLUDE_ALL) {
+                // [core#609]: do need to implement, but with 2.10.x TokenFilter no
+                // useful method to call so will be mostly unfiltered
+                /*
+                if (!state.includeString("")) {
+                    return;
+                }
+                */
+            }
+            _checkParentPath();
+        }
+        delegate.writeString(reader, len);
+    }
+
     @Override
     public void writeRawUTF8String(byte[] text, int offset, int length) throws IOException
     {

src/test/java/com/fasterxml/jackson/failing/TokenFilter609Test.java

@@ -0,0 +1,82 @@
+package com.fasterxml.jackson.failing;
+
+import java.io.*;
+
+import com.fasterxml.jackson.core.*;
+import com.fasterxml.jackson.core.filter.FilteringGeneratorDelegate;
+import com.fasterxml.jackson.core.filter.TokenFilter;
+import com.fasterxml.jackson.core.util.JsonGeneratorDelegate;
+
+// for [core#609]
+public class TokenFilter609Test
+    extends com.fasterxml.jackson.core.BaseTest
+{
+    static class NullExcludingTokenFilter extends TokenFilter {
+        private static final NullExcludingTokenFilter INSTANCE =
+                new NullExcludingTokenFilter();
+
+        @Override
+        public boolean includeNull() {
+            return false;
+        }
+
+    }
+
+    static class StringTruncatingGeneratorDelegate
+        extends JsonGeneratorDelegate
+    {
+        private final int maxStringLength;
+
+        private StringTruncatingGeneratorDelegate(
+                JsonGenerator jsonGenerator,
+                int maxStringLength) {
+            super(jsonGenerator);
+            this.maxStringLength = maxStringLength;
+        }
+
+        @Override
+        public void writeString(String text) throws IOException {
+            if (text == null) {
+                writeNull();
+            } else if (maxStringLength <= 0 || maxStringLength >= text.length()) {
+                super.writeString(text);
+            } else {
+//                super.writeString(text.substring(0, maxStringLength));
+                StringReader textReader = new StringReader(text);
+                super.writeString(textReader, maxStringLength);
+            }
+        }
+
+        @Override
+        public void writeFieldName(String name) throws IOException {
+            if (maxStringLength <= 0 || maxStringLength >= name.length()) {
+                super.writeFieldName(name);
+            } else {
+                String truncatedName = name.substring(0, maxStringLength);
+                super.writeFieldName(truncatedName);
+            }
+        }
+
+    }
+
+    // for [core#609]: will pass in 2.10 for some cases
+    @SuppressWarnings("resource")
+    public void testIssue609() throws Exception
+    {
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        JsonGenerator g = createGenerator(outputStream);
+        g = new FilteringGeneratorDelegate(
+                g, NullExcludingTokenFilter.INSTANCE, true, true);
+        int maxStringLength = 10;
+        g = new StringTruncatingGeneratorDelegate(
+                g, maxStringLength);
+        g.writeStartObject();
+        g.writeFieldName("message");
+        g.writeString("1234567890!");
+        g.writeEndObject();
+        g.close();
+
+        String json = outputStream.toString("US-ASCII");
+        assertEquals("{\"message\":\"1234567890\"}", json);
+    }
+}