added basic support of # (optional number) for decimals

Classes/PHPExcel/Style/NumberFormat.php

@@ -264,7 +264,7 @@ private static function fillBuiltInFormatCodes()
         //      40: "#,##0.00_);[Red](#,##0.00)"
         //      47: "mm:ss.0"
         //      KOR fmt 55: "yyyy/mm/dd"
- 
+
         // Built-in format codes
         if (is_null(self::$builtInFormats)) {
             self::$builtInFormats = array();
@@ -689,6 +689,8 @@ public static function toFormattedString($value = '0', $format = PHPExcel_Style_
                     // scale number
                     $value = $value / $scale;
 
+                    $decimalsFormat = strstr($format, '.');
+                    $optionalDecimalsCount = strlen($decimalsFormat) - strlen(rtrim($decimalsFormat, '#'));
                     // Strip #
                     $format = preg_replace('/\\#/', '0', $format);
 
@@ -723,6 +725,11 @@ public static function toFormattedString($value = '0', $format = PHPExcel_Style_
                             }
                         }
                     }
+
+                    while ($optionalDecimalsCount > 0 && substr($value, -1) === '0') {
+                        $value = substr($value, 0, -1);
+                        $optionalDecimalsCount--;
+                    }
                 }
                 if (preg_match('/\[\$(.*)\]/u', $format, $m)) {
                     //  Currency or Accounting

unitTests/rawTestData/Style/NumberFormat.data

@@ -8,7 +8,7 @@
 0.1,		"0.0",									"0.1"
 0.1,		"0",									"0"
 5.5555,		"0.###",								"5.556"
-5.5555,		"0.0##",								"5.556"	
+5.5555,		"0.0##",								"5.556"
 5.5555,		"0.00#",								"5.556"
 5.5555,		"0.000",								"5.556"
 5.5555,		"0.0000",								"5.5555"
@@ -35,3 +35,15 @@
 -123456789,	'0000:00:00',							"-12345:67:89"
 1234567.89,	'0000:00.00',							"12345:67.89"
 -1234567.89,'0000:00.00',							"-12345:67.89"
+12345.6789,	'"#,##0.##"',							'"12,345.68"'		// test case from above
+12345.6,	'"#,##0.00"',							'"12,345.60"'		// 0 means: show decimal
+12345.6,	'"#,##0.##"',							'"12,345.6"'		// # means: "cut off zeros"
+12345,		'"#,##0.00"',							'"12,345.00"'		// 0 means: show decimal
+12345,		'"#,##0.##"',							'"12,345."'			// # means: "cut off zeros" (decimal separator can not be made optional by excel)
+12345.6789,	'"#,##0.0#"',							'"12,345.68"'		// first not optional, second optional
+12345.6,	'"#,##0.0#"',							'"12,345.6"'		// first not optional, second optional
+12345,		'"#,##0.0#"',							'"12,345.0"'		// first not optional, second optional
+12345.6789,	'"#,##0.000#"',							'"12,345.6789"'
+12345.6,	'"#,##0.000#"',							'"12,345.600"'
+12345.6789,	'"#,##0.0#0#"',							'"12,345.6789"'		// treated like .000#
+12345.6,	'"#,##0.0#0#"',							'"12,345.600"'		// treated like .000#