550D crashes when trying to "Q" in to Vignetting options

Issue #1840 resolved
Former user created an issue

Build 2014-01-26 17:23:15 -0800 on 550D crashes when trying to "Q" in to Vignetting options, battery has to be removed. However everything is fine if I just switch Vignetting on. I don't know what build I was on last, but it worked maybe some time in Nov or Dec.

Comments (12)

  1. Albert Shih

    I can confirm that my 50D becomes unresponsive when trying to access the Vignetting options. Stepping through the commits, this bug was introduced just last week in commit f442534, when the rand() function was replaced.

    The old rand() returned only positive signed integers. The new rand() attempts to return a positive signed integer, but instead calls ABS on an unsigned integer before then casting it to a signed integer. I don't understand lv-img-engio.c well enough to understand why this causes a problem (on only some cameras), but changing the return statement of rand() to

        return ABS((int)ret);

    fixes the problem.

    Edit: fixed the code statement

  2. andrus9000

    Hi guys, same problem with my 5D2, the camera freezes and stop responding when I press Q to enter the Vignetting menu, there is no log in my card. Using nightly build 2014-01-28

  3. Georg Hofstetter

    thanks for fixing, didnt notice that nasty bug. indeed masking out the uppermost bit (& ~0x80000000) would be the cheaper way.

    the good thing about that changes, i've tested our RNG implementations and they show both about equal byte distributions and dont catasrophically fail all diehard tests. (as ive ran the test "only" 30 million times, i guess the rgb_lagged_sum tests caught that repetition) implementations tested: mersenne twister (100 Megabyte) and LFSR113 (20 GigaByte) with system timer as salt. LFSR113 without timer was a bit weaker with some tests.

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