Some tweaks and fixes for Common::Rational

* Fix Common::gcd to work with negative input
* This fixes a bug in Common::Rational's multiplication code
* Add some more basic unit tests (including one which checks for
  the now fixed multiplication bug)
* cleanup

svn-id: r49064

2 files changed, 3 insertions, 25 deletions

diff --git a/common/algorithm.h b/common/algorithm.h
index 06f2a279af..d3f518b225 100644
--- a/common/algorithm.h
+++ b/common/algorithm.h
@@ -227,6 +227,8 @@ void sort(T first, T last) {
  */
 template<class T>
 T gcd(T a, T b) {
+	if (a <= 0) a = -a;
+	if (b <= 0) b = -b;
 	while (a > 0) {
 		T tmp = a;
 		a = b % a;
diff --git a/common/rational.cpp b/common/rational.cpp
index e27e880a04..91d1c5a848 100644
--- a/common/rational.cpp
+++ b/common/rational.cpp
@@ -49,7 +49,7 @@ Rational::Rational(int num, int denom) {
 
 void Rational::cancel() {
 	// Cancel the fraction by dividing both the num and the denom
-	// by their greatest common denom.
+	// by their greatest common divisor.
 
 	int gcd = Common::gcd(_num, _denom);
 
@@ -144,65 +144,49 @@ const Rational Rational::operator-() const {
 
 const Rational Rational::operator+(const Rational &right) const {
 	Rational tmp = *this;
-
 	tmp += right;
-
 	return tmp;
 }
 
 const Rational Rational::operator-(const Rational &right) const {
 	Rational tmp = *this;
-
 	tmp -= right;
-
 	return tmp;
 }
 
 const Rational Rational::operator*(const Rational &right) const {
 	Rational tmp = *this;
-
 	tmp *= right;
-
 	return tmp;
 }
 
 const Rational Rational::operator/(const Rational &right) const {
 	Rational tmp = *this;
-
 	tmp /= right;
-
 	return tmp;
 }
 
 const Rational Rational::operator+(int right) const {
 	Rational tmp = *this;
-
 	tmp += right;
-
 	return tmp;
 }
 
 const Rational Rational::operator-(int right) const {
 	Rational tmp = *this;
-
 	tmp -= right;
-
 	return tmp;
 }
 
 const Rational Rational::operator*(int right) const {
 	Rational tmp = *this;
-
 	tmp *= right;
-
 	return tmp;
 }
 
 const Rational Rational::operator/(int right) const {
 	Rational tmp = *this;
-
 	tmp /= right;
-
 	return tmp;
 }
 
@@ -296,33 +280,25 @@ Rational::operator double() const {
 
 const Rational operator+(int left, const Rational &right) {
 	Rational tmp = right;
-
 	tmp += left;
-
 	return tmp;
 }
 
 const Rational operator-(int left, const Rational &right) {
 	Rational tmp = right;
-
 	tmp -= left;
-
 	return tmp;
 }
 
 const Rational operator*(int left, const Rational &right) {
 	Rational tmp = right;
-
 	tmp *= left;
-
 	return tmp;
 }
 
 const Rational operator/(int left, const Rational &right) {
 	Rational tmp = right;
-
 	tmp /= left;
-
 	return tmp;
 }