csv: remove old workaround in UTF8Reader

Author: pjfanning

csv/src/main/java/com/fasterxml/jackson/dataformat/csv/impl/UTF8Reader.java

@@ -403,19 +403,6 @@ private boolean loadMore(int available) throws IOException
         // Bytes that need to be moved to the beginning of buffer?
         if (available > 0) {
             if (_inputPtr > 0) {
-                if (!canModifyBuffer()) {
-                    // 15-Aug-2022, tatu: Occurs (only) if we have half-decoded UTF-8
-                    //     characters; uncovered by:
-                    //
-                    // https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=50036
-                    //
-                    // and need to be reported as IOException
-                    if (_inputSource == null) {
-                        throw new IOException(String.format(
-"End-of-input after first %d byte(s) of a UTF-8 character: needed at least one more",
-available));
-                    }
-                }
                 for (int i = 0; i < available; ++i) {
                     _inputBuffer[i] = _inputBuffer[_inputPtr+i];
                 }

csv/src/test/java/com/fasterxml/jackson/dataformat/csv/deser/FuzzCSVReadTest.java

@@ -25,8 +25,7 @@ public void testUTF8Decoding50036() throws Exception
             CSV_MAPPER.readTree(INPUT);
             fail("Should not pass");
         } catch (IOException e) {
-            verifyException(e, "End-of-input after first 1 byte");
-            verifyException(e, "of a UTF-8 character");
+            verifyException(e, "Unexpected EOF in the middle of a multi-byte UTF-8 character");
         }
     }
 

csv/src/test/java/com/fasterxml/jackson/dataformat/csv/tofix/UnicodeCSVRead497Test.java renamed to csv/src/test/java/com/fasterxml/jackson/dataformat/csv/deser/UnicodeCSVRead497Test.java

@@ -1,4 +1,4 @@
-package com.fasterxml.jackson.dataformat.csv.tofix;
+package com.fasterxml.jackson.dataformat.csv.deser;
 
 import java.io.ByteArrayInputStream;
 import java.nio.charset.StandardCharsets;
@@ -8,7 +8,6 @@
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.dataformat.csv.CsvMapper;
 import com.fasterxml.jackson.dataformat.csv.ModuleTestBase;
-import com.fasterxml.jackson.dataformat.csv.testutil.failure.JacksonTestFailureExpected;
 
 import static org.junit.jupiter.api.Assertions.*;
 
@@ -18,7 +17,6 @@ public class UnicodeCSVRead497Test extends ModuleTestBase
     private final CsvMapper MAPPER = mapperForCsv();
 
     // [dataformats-text#497]
-    @JacksonTestFailureExpected
     @Test
     public void testUnicodeAtEnd() throws Exception
     {