Merge pull request #1348 from carsonmcdonald/shiftwarningfix

Fix signed/unsigned warning in numeric shift

src/numeric.c

@@ -998,7 +998,7 @@ fix_xor(mrb_state *mrb, mrb_value x)
 #define NUMERIC_SHIFT_WIDTH_MAX (sizeof(mrb_int)*CHAR_BIT-1)
 
 static mrb_value
-lshift(mrb_state *mrb, mrb_int val, int width)
+lshift(mrb_state *mrb, mrb_int val, size_t width)
 {
   if (width > NUMERIC_SHIFT_WIDTH_MAX) {
     mrb_raisef(mrb, E_RANGE_ERROR, "width(%S) > (%S:sizeof(mrb_int)*CHAR_BIT-1)",
@@ -1010,7 +1010,7 @@ lshift(mrb_state *mrb, mrb_int val, int width)
 }
 
 static mrb_value
-rshift(mrb_int val, int width)
+rshift(mrb_int val, size_t width)
 {
   if (width >= NUMERIC_SHIFT_WIDTH_MAX) {
     if (val < 0) {

test/t/integer.rb

@@ -104,6 +104,14 @@ assert('Integer#<<', '15.2.8.3.12') do
   #   00010111 (23)
   # = 00101110 (46)
   assert_equal 23 << 1, 46
+
+  # Left Shift by a negative is Right Shift
+  assert_equal 46 << -1, 23
+
+  # Raise when shift is too large
+  assert_raise(RangeError) do
+    2 << 128
+  end
 end
 
 assert('Integer#>>', '15.2.8.3.13') do
@@ -111,6 +119,17 @@ assert('Integer#>>', '15.2.8.3.13') do
   #   00101110 (46)
   # = 00010111 (23)
   assert_equal 46 >> 1, 23
+
+  # Right Shift by a negative is Left Shift
+  assert_equal 23 >> -1, 46
+
+  # Don't raise on large Right Shift
+  assert_equal 23 >> 128, 0
+
+  # Raise when shift is too large
+  assert_raise(RangeError) do
+    2 >> -128
+  end
 end
 
 assert('Integer#ceil', '15.2.8.3.14') do