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| author | Yukihiro Matsumoto <[email protected]> | 2012-06-13 19:05:33 +0900 |
|---|---|---|
| committer | Yukihiro Matsumoto <[email protected]> | 2012-06-13 19:05:33 +0900 |
| commit | 8e574a9e7433cb6f5b17a8cac8e66a54fc71a03f (patch) | |
| tree | bdb490fa88052d583468e84dd679cea29fea66c4 /src/numeric.c | |
| parent | 2ded555a91a63744fcc20bdd67c50ff113095303 (diff) | |
| download | mruby-8e574a9e7433cb6f5b17a8cac8e66a54fc71a03f.tar.gz mruby-8e574a9e7433cb6f5b17a8cac8e66a54fc71a03f.zip | |
integer overflow in fixnum plus and minus
Diffstat (limited to 'src/numeric.c')
| -rw-r--r-- | src/numeric.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/numeric.c b/src/numeric.c index 81933237e..746078fd9 100644 --- a/src/numeric.c +++ b/src/numeric.c @@ -1073,7 +1073,8 @@ mrb_fixnum_plus(mrb_state *mrb, mrb_value x, mrb_value y) b = mrb_fixnum(y); c = a + b; - if (c - b != a) { + if (((a < 0) ^ (b < 0)) == 0 && (a < 0) != (c < 0)) { + /* integer overflow */ return mrb_float_value((mrb_float)a + (mrb_float)b); } return mrb_fixnum_value(c); @@ -1111,7 +1112,8 @@ mrb_fixnum_minus(mrb_state *mrb, mrb_value x, mrb_value y) b = mrb_fixnum(y); c = a - b; - if (c + b != a) { + if (((a < 0) ^ (b < 0)) != 0 && (a < 0) != (c < 0)) { + /* integer overflow */ return mrb_float_value((mrb_float)a - (mrb_float)b); } return mrb_fixnum_value(c); |