* test/manual/image-circular-tests.el
(image-test-duplicate-keywords): Skip unless images are supported.
(image-test-circular-plist, image-test-:type-property-value): Ditto.
Wrap only failing forms in should[-error] rather than entire test
bodies. Use simpler printed notation in place of function calls.
(image-test-circular-specs): Ditto. Wrap overly wide docstring.
Mark as failing since shortly after its introduction (bug#36403#63).
* test/manual/biditest.el: Use lexical-binding.
(biditest-generate-testfile): Remove unused var `levels`.
* test/manual/image-circular-tests.el: Use lexical-binding.
* test/manual/image-size-tests.el: Use lexical-binding.
(image-size-tests): Check `fboundp` before calling `imagemagick-types`.
* test/manual/redisplay-testsuite.el: Use lexical-binding.
* test/manual/cedet/cedet-utests.el: Use lexical-binding.
Use `with-current-buffer`.
(cedet-utest): Test `fboundp` i.s.o `featurep` to silence warning.
(srecode-map-save-file): Declare var.
(pulse-test): Test `fboundp` before calling `pulse-available-p`.
Declare `pulse-momentary-highlight-overlay` since it's not autoloaded.
* test/manual/cedet/semantic-tests.el: Use lexical-binding.
Use `with-current-buffer`.
(semanticdb-ebrowse-dump): Remove unused var `ab`.
(semanticdb-test-gnu-global): Don't use obsolete "name" arg to constructor.
(cedet-utest-directory): Declare var.
* test/src/image-tests.el (image-test-circular-specs): New file.
* src/image.c (parse_image_spec): Return failure for circular lists.
(valid_image_p): Don't look at odd-numbered list elements expecting to
find a property name.
(image_spec_value): Handle circular lists.
(equal_lists): Introduce.
(search_image_cache): Use `equal_lists' (bug#36403).
