Dear Jean-Philippe, from my point of view (I am not a developer) it looks like this is the same bug as 833532 (and the merged bugs). I suggest you to set "javascript.options.baselinejit" to "false" in about:config. If this fixes your problem, this is an indicator that your bug is the same as 833532. I think you have to set this option in safe mode because for me icedove crashes when I try to open about:config with version 1:45.2.0-2+b1. Or you downgrade to an older version of icedove, set the option and then upgrade again to test it.
Regards Viktor
