fixes #13363

Links:
 * http://www.daveperrett.com/articles/2012/07/28/exif-orientation-handling-is-a-ghetto/
 * Example data: https://github.com/recurser/exif-orientation-examples

filesize(null) yields an int on HHVM and thus exif_imagetype(null) is called.

This checks that imagecreatetruecolor actually creates an image, rather than returning FALSE.
Without this check, subsequent loop might create billions of ERROR-level log messages.

Signed-off-by: Byron Marohn <combustible@live.com>

TIFFs also have EXIF headers, but they're not supported by the Image class

PHP doc
http://php.net/manual/en/function.exif-read-data.php

Fix #7148 - again :)

ref #10392

* test case added to avoid adding them later

using scrutinizer patch

This patch was automatically generated as part of the following inspection:
https://scrutinizer-ci.com/g/owncloud/core/inspections/cdfecc4e-a37e-4233-8025-f0d7252a8720

Enabled analysis tools:
 - PHP Analyzer
 - JSHint
 - PHP Copy/Paste Detector
 - PHP PDepend

imagerotate() with third parameter being -1 does not seem to work in PHP 5.5

loadFromBase64() one up, so debug-logs aren't spammed (as much) with urlencoded
base64-data from loadFromFile() debug output.

This reverts commit 3488f0b7.

no user is logged in (e.g. public gallery share)

Conflicts:
	lib/private/vcategories.php

a 'valid path', but only a data/base64-string.

Related to #4283

don't try to extract image infos from 0- or better less than 12 byte length files. See description of `exif_imagetype` function at
`http://php.net/manual/de/function.exif-imagetype.php`.