diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | Src/math.c | 26 |
2 files changed, 29 insertions, 4 deletions
diff --git a/ChangeLog b/ChangeLog index ff8c8f666..a546a3f50 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2012-09-06 Peter Stephenson <p.w.stephenson@ntlworld.com> + + * 30656: Src/math.c: treat dividing by -1 the same as + multiplying by it to get around SIGFPE. + 2012-09-05 Peter Stephenson <pws@csr.com> * Jun T.: 30658: Completion/Unix/Command/_uniq: more options. @@ -137,5 +142,5 @@ ***************************************************** * This is used by the shell to define $ZSH_PATCHLEVEL -* $Revision: 1.5715 $ +* $Revision: 1.5716 $ ***************************************************** diff --git a/Src/math.c b/Src/math.c index cca521098..c7d384019 100644 --- a/Src/math.c +++ b/Src/math.c @@ -1053,14 +1053,34 @@ op(int what) return; if (c.type == MN_FLOAT) c.u.d = a.u.d / b.u.d; - else - c.u.l = a.u.l / b.u.l; + else { + /* + * Avoid exception when dividing the smallest + * negative integer by -1. Always treat it the + * same as multiplication. This still doesn't give + * numerically the right answer in two's complement, + * but treating both these in the same way seems + * reasonable. + */ + if (b.u.l == -1) + c.u.l = - a.u.l; + else + c.u.l = a.u.l / b.u.l; + } break; case MOD: case MODEQ: if (!notzero(b)) return; - c.u.l = a.u.l % b.u.l; + /* + * Avoid exception as above. + * Any integer mod -1 is the same as any integer mod 1 + * i.e. zero. + */ + if (b.u.l == -1) + c.u.l = 0; + else + c.u.l = a.u.l % b.u.l; break; case PLUS: case PLUSEQ: |