[wp-trac] [WordPress Trac] #18532: resized image dimensions incorrectly floored instead of rounded

[WordPress Trac]

#18532: resized image dimensions incorrectly floored instead of rounded
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 Reporter:  _ck_                     |       Owner:  SergeyBiryukov
     Type:  defect (bug)             |      Status:  assigned
 Priority:  normal                   |   Milestone:  4.1
Component:  Media                    |     Version:  2.5
 Severity:  normal                   |  Resolution:
 Keywords:  has-patch needs-refresh  |     Focuses:
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Comment (by kitchin):

 Patch 18532k.diff does this:

 1. Adjusts resize tests to match new behavior where it is off by one pixel
 from old behavior. I forgot to make a test to fail the bug report, so we
 need to do that still. The new numbers agree with IrfanView, Photoshop,
 any web browser, etc., of course. Because they round. This shows we need
 the patch.

 2. Changes a bunch of `assertEquals()` to assertSame()` because the
 function should continue to return integers, not floats that look like
 integers.

 3. I put the same rounding fix in image_resize_dimensions() for cropping.

 4. I have some xxx comments that need to be resolved or deleted.

 5. Getting scary looking console errors on my CentOS 5 system cPanel with
 ImageMagick 6.2.8 (yum up to date), so I disabled the unit tests that try
 to load a PNG or GIF when Worpdress decides ImageMagick only supports JPG
 (iterator support). They try to load a WP_Error object back into
 ImageMagick. Instead I did markTestSkipped() when

 5a. WP_Error reached in PNG or GIF test.

 5b. Any call to test_resize_bad_image() with ImageMagick is skipped.

 We will probably want a patch without the (5b) change, or condition (5b)
 on PNG support. There no need for the (5a) console errors at all, they
 need to be either assertions or skips.

 I kept the assert on ImageMagick PNG support in general, so you still get
 one Fail. (That makes it skip the assert for GIF support.)

 6. Existing code could use some style cleanup.


 Proposed changes for next patch:

 * Make a test this bug fails.
 * Condition (5b) Skip on no ImageMagick PNG support.
 * Fix xxx comments.

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Ticket URL: <https://core.trac.wordpress.org/ticket/18532#comment:9>
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