Merge branch 'pr/70'

# Conflicts:
#	tests/Omnipay/Common/Message/AbstractRequestTest.php

Author: barryvdh

src/Omnipay/Common/Message/AbstractRequest.php

@@ -335,7 +335,7 @@ public function getAmount()
             }
 
             // Check for rounding that may occur if too many significant decimal digits are supplied.
-            $decimal_count = strlen(substr(strrchr((string)$amount, '.'), 1));
+            $decimal_count = strlen(substr(strrchr(sprintf('%.8g', $amount), '.'), 1));
             if ($decimal_count > $this->getCurrencyDecimalPlaces()) {
                 throw new InvalidRequestException('Amount precision is too high for currency.');
             }

tests/Omnipay/Common/Message/AbstractRequestTest.php

@@ -124,6 +124,41 @@ public function testAmountZeroNotAllowed()
         $this->changeProtectedProperty('zeroAmountAllowed', false);
         $this->request->setAmount('0.00');
         $this->request->getAmount();
+	}
+
+    // See https://github.com/thephpleague/omnipay-common/issues/69
+    public function testAmountPrecision()
+    {
+        // The default precision for PHP is 6 decimal places.
+        ini_set('precision', 6);
+        $this->assertSame($this->request, $this->request->setAmount('67.10'));
+        $this->assertSame('67.10', $this->request->getAmount());
+
+        // At 17 decimal places, 67.10 will echo as 67.09999...
+        // This is *why* PHP sets the default precision at 6.
+        ini_set('precision', 17);
+        $this->assertSame('67.10', $this->request->getAmount());
+
+        $this->assertSame($this->request, $this->request->setAmount('67.01'));
+        $this->assertSame('67.01', $this->request->getAmount());
+
+        $this->assertSame($this->request, $this->request->setAmount('0.10'));
+        $this->assertSame('0.10', $this->request->getAmount());
+
+        $this->assertSame($this->request, $this->request->setAmount('0.01'));
+        $this->assertSame('0.01', $this->request->getAmount());
+    }
+
+    /**
+     * @expectedException Omnipay\Common\Exception\InvalidRequestException
+     *
+     * We still want to catch obvious fractions of the minor units that are
+     * not precision errors at a much lower level.
+     */
+    public function testAmountPrecisionTooHigh()
+    {
+        $this->assertSame($this->request, $this->request->setAmount('123.005'));
+        $this->assertSame('123.005', $this->request->getAmount());
     }
 
     public function testGetAmountNoDecimals()