bug#18126: 24.4.50; Arithmetic range error while attempting to drag vertical scroll bar

[martin rudalics]

> Using Lucid build, an attempt to drag slider of a vertical scroll bar
> with mouse causes an arithmetic error:
>
> Arithmetic range error: "truncate", 1.0e+INF
>
> Corresponding buffer should have enough (a few thousands) lines.
>
> The backtrace is:
>
> Breakpoint 4, rounding_driver (arg=..., divisor=..., double_round=0x6197d1 
<double_identity>, int_round2=0x6196c2 <truncate2>,
>      name=0x71f78b "truncate") at ../../trunk/src/floatfns.c:372
> 372             xsignal2 (Qrange_error, build_string (name), arg);
> (gdb) bt
> #0  rounding_driver (arg=..., divisor=..., double_round=0x6197d1 <double_identity>, 
int_round2=0x6196c2 <truncate2>,
>      name=0x71f78b "truncate") at ../../trunk/src/floatfns.c:372

Should work again now.  Please check.

Thanks, martin