Fix #191

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

@@ -505,44 +505,68 @@ public boolean startNewLine() throws IOException
      * @since 2.10.1
      */
     public boolean skipLinesWhenNeeded() throws IOException {
-        if (!(_allowComments || _skipBlankLines)) {
+        if (_allowComments) {
+            return _skipCommentLines();
+        }
+        if (!_skipBlankLines) {
             return hasMoreInput();
         }
-        int firstCharacterPtr = _inputPtr;
+
+        // only need to skip fully empty lines
         while (hasMoreInput()) {
-            char ch = _inputBuffer[_inputPtr++];
+            char ch = _inputBuffer[_inputPtr];
             if (ch == '\r' || ch == '\n') {
+                ++_inputPtr;
                 _pendingLF = ch;
                 _handleLF();
-                // track the start of the new line
-                firstCharacterPtr = _inputPtr;
                 continue;
             }
-            if (ch == ' ') {
+            if (ch != ' ') {
+                return true; // processing can go on
+            }
+            ++_inputPtr;
+        }
+        return false; // end of input
+    }
+
+    public boolean _skipCommentLines() throws IOException
+    {
+        while ((_inputPtr < _inputEnd) || loadMore()) {
+            char ch = _inputBuffer[_inputPtr];
+            switch (ch) {
+            case '#':
+                ++_inputPtr;
+                _skipCommentContents();
+                continue;
+            case '\r':
+            case '\n':
+                ++_inputPtr;
+                _pendingLF = ch;
+                _handleLF();
+                continue;
+            case ' ':
                 // skip all blanks (in both comments/blanks skip mode)
+                ++_inputPtr;
                 continue;
+            default:
+                return true;
             }
-            if (_allowComments) {
-                if (_inputBuffer[firstCharacterPtr] == '#') {
-                    // on a commented line, skip everything
-                    continue;
-                }
-                if (ch == '#') {
-                    // we reach this point when whitespaces precedes the hash character
-                    // move the firstCharacterPtr to the '#' location in order to skip the line completely
-                    firstCharacterPtr = _inputPtr-1;
-                    continue;
-                }
-            }
-            // we reached a non skippable character, this line needs to be parsed
-            // rollback the input pointer to the beginning of the line
-            _inputPtr = firstCharacterPtr;
-            return true; // processing can go on
         }
         return false; // end of input
     }
 
-    // 12-Apr-2020, tatu: Not used any more (probably replaced by above?)
+    private void _skipCommentContents() throws IOException
+    {
+        while ((_inputPtr < _inputEnd) || loadMore()) {
+            char ch = _inputBuffer[_inputPtr++];
+            if (ch == '\r' || ch == '\n') {
+                _pendingLF = ch;
+                _handleLF();
+                break;
+            }
+        }
+    }
+
     /*
     private final static int INT_HASH = '#';
 
@@ -559,7 +583,8 @@ protected int _skipCommentLines() throws IOException
             // Ok, skipped the end of the line. Check next one...
             int i = _nextChar();
             if (i != INT_HASH) {
-                return i;
+                --_inputPtr;
+                return true;
             }
         }
         return -1; // end of input

csv/src/test/java/com/fasterxml/jackson/dataformat/csv/deser/SkipBlankLines15Test.java → csv/src/test/java/com/fasterxml/jackson/dataformat/csv/deser/SkipEmptyLines15Test.java

@@ -9,7 +9,7 @@
 import static org.junit.Assert.assertArrayEquals;
 
 // for [dataformats-text#15]: Allow skipping of empty lines
-public class SkipBlankLines15Test extends ModuleTestBase {
+public class SkipEmptyLines15Test extends ModuleTestBase {
 
     private static final String CSV_WITH_EMPTY_LINE = "1,\"xyz\"\n\ntrue,\n";
     private static final String CSV_WITH_BLANK_LINE = "1,\"xyz\"\n   \ntrue,\n";
@@ -129,14 +129,18 @@ public void testCsvWithBlankLineAndCommentSkipBlankLinesFeatureDisabled() throws
         ), rows);
     }
 
+    // 14-Apr-2020, tatu: Due to [dataformats-text#191], can not retain leading spaces
+    //   when trimming empty lines and/or comments, so test changed for 2.11
     public void testCsvWithBlankLineAndCommentSkipBlankLinesFeatureEnabled() throws Exception {
         String[][] rows = mapperForCsvAsArray()
                 .with(CsvParser.Feature.SKIP_EMPTY_LINES)
                 .readValue(CSV_WITH_BLANK_LINE_AND_COMMENT);
         // blank/empty lines are skipped
         assertArrayEquals(expected(
                 row("1", "xyz"),
-                row("  #comment"),
+                // As per: [dataformats-text#191]
+//                row("  #comment"),
+                row("#comment"),
                 row("true", "")
         ), rows);
     }

csv/src/test/java/com/fasterxml/jackson/dataformat/csv/failing/ParserSkipEmpty191Test.java → csv/src/test/java/com/fasterxml/jackson/dataformat/csv/deser/SkipEmptyLines191Test.java

@@ -1,4 +1,4 @@
-package com.fasterxml.jackson.dataformat.csv.failing;
+package com.fasterxml.jackson.dataformat.csv.deser;
 
 import java.io.Reader;
 import java.io.StringReader;
@@ -10,7 +10,7 @@
 import com.fasterxml.jackson.dataformat.csv.ModuleTestBase;
 
 // [dataformats-text#191]
-public class ParserSkipEmpty191Test extends ModuleTestBase {
+public class SkipEmptyLines191Test extends ModuleTestBase {
 
     private static String COL_1 = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
     private static String COL_2 = "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb";

release-notes/VERSION-2.x

@@ -18,6 +18,8 @@ Modules:
 #180: (yaml) YAMLGenerator serializes string with special chars unquoted when
   using `MINIMIZE_QUOTES` mode
  (reported, fix contributed by Timo R)
+#191: (csv) `ArrayIndexOutOfBoundsException` when skipping empty lines, comments
+ (reported by f-julian@github)
 
 2.10.4 (not yet released)