Comment 8 for bug 374524

I've changed the summary, because

a) The true cause of this bug is not the javascript being malformed (mixing up
arithmetical operation and string concatenation) but the large number resulting
from that malformed term.

b) This can lead to much more serious problems. If the width and heigth
parameters are extremely large (~100000, as in my testcase), Mozilla simply
crashes (not too dangerous). But with somewhat smaller values Mozilla seems to
allocate endless amounts of memory, rendering the whole system unusable.

I've tried

  window.open('','win','width=10000,height=10000');

and the only way to get out of it was to kill the X server.