ISSUE-115 - to_char fails with pattern FM0D099

h2/src/docsrc/html/changelog.html

@@ -27,13 +27,15 @@ Change Log
 </li>
 <li>Issue #186: The "script" command did not include sequences of temporary tables.
 </li>
+<li>Issue #115: to_char fails with pattern FM0D099
+</li>
 </ul>
 
 <h2>Version 1.4.190 Beta (2015-10-11)</h2>
 <ul>
 <li>Pull request #183: optimizer hints (so far without special SQL syntax).
 </li>
-<li>Issue #180: In MVCC mode, executing UPDATE and SELECT ... FOR UPDATE 
+<li>Issue #180: In MVCC mode, executing UPDATE and SELECT ... FOR UPDATE
     simultaneously silently can drop rows.
 </li>
 <li>PageStore storage: the cooperative file locking mechanism

h2/src/main/org/h2/util/ToChar.java

@@ -11,6 +11,7 @@ import java.sql.Timestamp;
 import java.text.DecimalFormat;
 import java.text.DecimalFormatSymbols;
 import java.text.SimpleDateFormat;
+import java.util.Arrays;
 import java.util.Calendar;
 import java.util.Currency;
 import java.util.GregorianCalendar;
@@ -219,7 +220,7 @@ public class ToChar {
         }
 
         StringBuilder output = new StringBuilder();
-        String unscaled = number.unscaledValue().abs().toString();
+        String unscaled = (number.abs().compareTo(BigDecimal.ONE) < 0 ? zeroesAfterDecimalSeparator(number) : "") + number.unscaledValue().abs().toString();
 
         // start at the decimal point and fill in the numbers to the left,
         // working our way from right to left
@@ -328,6 +329,26 @@ public class ToChar {
         return output.toString();
     }
 
+    private static String zeroesAfterDecimalSeparator(BigDecimal number) {
+        final String numberStr = number.toString();
+        final int idx = numberStr.indexOf('.');
+        if (idx >= 0 ) {
+            int i = idx + 1;
+            boolean allZeroes = true;
+            for (; i < numberStr.length(); i++) {
+                if (numberStr.charAt(i) != '0') {
+                    allZeroes = false;
+                    break;
+                }
+            }
+            final char[] zeroes = new char[allZeroes ? numberStr.length() - idx - 1: i - 1 - idx];
+            Arrays.fill(zeroes, '0');
+            return String.valueOf(zeroes);
+        } else {
+            return "";
+        }
+    }
+
     private static void addSign(StringBuilder output, int signum,
             boolean leadingSign, boolean trailingSign, boolean trailingMinus,
             boolean angleBrackets, boolean fillMode) {

h2/src/test/org/h2/test/db/TestFunctions.java

@@ -1699,6 +1699,24 @@ public class TestFunctions extends TestBase implements AggregateFunction {
         assertThrows(ErrorCode.INVALID_TO_CHAR_FORMAT, stat,
                 "SELECT TO_CHAR(123.45, 'q999.99') FROM DUAL");
 
+        // ISSUE-115
+        assertResult("0.123", stat, "select to_char(0.123, 'FM0.099') from dual;");
+        assertResult("1.123", stat, "select to_char(1.1234, 'FM0.099') from dual;");
+        assertResult("1.1234", stat, "select to_char(1.1234, 'FM0.0999') from dual;");
+        assertResult("1.023", stat, "select to_char(1.023, 'FM0.099') from dual;");
+        assertResult("0.012", stat, "select to_char(0.012, 'FM0.099') from dual;");
+        assertResult("0.123", stat, "select to_char(0.123, 'FM0.099') from dual;");
+        assertResult("0.001", stat, "select to_char(0.001, 'FM0.099') from dual;");
+        assertResult("0.001", stat, "select to_char(0.0012, 'FM0.099') from dual;");
+        assertResult("0.002", stat, "select to_char(0.0019, 'FM0.099') from dual;");
+        assertResult("0.0", stat, "select to_char(0, 'FM0D099') from dual;");
+        assertResult("0.00", stat, "select to_char(0., 'FM0D009') from dual;");
+        assertResult("0.", stat, "select to_char(0, 'FM0D9') from dual;");
+        assertResult("0.0", stat, "select to_char(0.0, 'FM0D099') from dual;");
+        assertResult("0.00", stat, "select to_char(0.00, 'FM0D009') from dual;");
+        assertResult("0.00", stat, "select to_char(0, 'FM0D009') from dual;");
+        assertResult("0.0", stat, "select to_char(0, 'FM0D09') from dual;");
+        assertResult("0.0", stat, "select to_char(0, 'FM0D0') from dual;");
         conn.close();
     }