M5: a comment whose colour is written [r g b null] is drawn, as CMYK with the null read as 0 (view.render-annotation-appearances) (#6503)

* M5: a comment whose colour is written [r g b null] is drawn, as CMYK with the null read as 0 (view.render-annotation-appearances)

ISO 32000-2 Table 166 /C (and /IC, Tables 178, 180, 181; /MK /BC and /BG,
Table 192) is an array of 0, 1, 3 or 4 numbers whose length picks the
colour space. A four-entry array with a non-number in it, such as
[1 0 0 null] (PDFBOX-2699), made the /C parser give up, so a shape
without an appearance stream was not drawn at all. PDFium, MuPDF and
Poppler all read such an array as CMYK with the non-number as 0.

- annot: a four-entry /C or /IC reads non-numbers as 0; other lengths
  still need every entry to be a number.
- annot: the properties' fill uses the same parser (it read
  [r g b null] as RGB before), and /C no longer drops a non-number
  to make three numbers.
- forms: /MK /BC and /BG read a four-entry array the same way instead
  of dropping the non-number and drawing RGB.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn

* M5: comment properties report the stroke colour as drawn; a reference among four colour entries is not read as 0 (view.render-annotation-appearances)

props() reads a non-FreeText /C through the appearance parser, so a
[1 0 0 null] stroke reports CMYK cyan as drawn, and grey and CMYK
strokes report their converted colour. A reference among the four
entries of a /C array (ISO 32000-2 7.3.10) is left unreadable instead
of standing in as 0, so /C [1 0 0 6 0 R] is never drawn cyan.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn

* M5: re-run CI (fill_sign Escape test depends on the clock's second, passes locally)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn

* M5: the comment list reports a comment's colour as drawn (view.render-annotation-appearances)

summaries() accepted only a three-entry /C, so a Square with /C [1 0 0 null],
drawn cyan and reported cyan by props(), had no colour in the comment list;
grey and CMYK colours were dropped the same way. Non-FreeText comments now
read /C through drawn_color (the array itself followed when it is given by
reference), keeping the three-number fallback and the FreeText /DA handling.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn

* M5: the render inspector lists a comment's colour as drawn (view.render-annotation-appearances)

The inspector accepted only a three-entry /C, with a referenced entry read
as 0, so a /C [1 0 0 null], a grey or a CMYK colour listed none, unlike the
comment list and the drawing. Non-FreeText comments now read /C by the
appearance builder's rule (one entry grey, four CMYK with a non-number as 0
and a reference unreadable, finite and clamped), with the three-number
fallback reading referenced entries.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn

---------

Co-authored-by: mtlcl410 <chuanlin@niar.org.tw>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

parity/acrobat-features.toml

@@ -818,8 +818,8 @@ milestone = "M2"
 status = "shipped"
 commands = []
 tools = []
-evidence = ["crates/render/src/raster/tests.rs::widget_appearance_states", "crates/render/src/raster/tests.rs::highlights_without_an_appearance_are_drawn", "crates/engine/src/tests.rs::comments_without_appearances_are_drawn_but_not_saved", "crates/engine/src/tests.rs::cli_display_adds_missing_appearances_without_changing_the_source", "crates/engine/src/tests.rs::fields_left_to_the_viewer_are_displayed_from_their_values", "crates/forms/src/tests.rs::need_appearances_draws_every_text_and_choice_field_in_the_display_copy", "crates/forms/src/tests.rs::the_field_appearance_cache_sees_every_input", "crates/engine/src/tests.rs::buttons_and_combs_left_to_the_viewer_are_displayed", "crates/forms/src/tests.rs::check_boxes_without_an_appearance_show_their_caption_symbol", "crates/forms/src/tests.rs::push_buttons_without_an_appearance_show_their_caption_and_frame", "crates/forms/src/tests.rs::need_appearances_draws_check_boxes_and_radio_buttons_from_their_captions", "crates/engine/src/tests.rs::need_appearances_buttons_are_displayed_from_their_captions", "crates/render/src/raster/tests.rs::invisible_unknown_annotations_and_popups_paint_nothing", "crates/print/src/tests.rs::invisible_annotations_of_unknown_types_do_not_print", "crates/engine/src/tests.rs::stamps_without_appearances_draw_the_stamp_they_name", "crates/automation/tests/it/automation.rs::page_render_draws_stamps_without_an_appearance"]
-notes = "comments without /AP (FreeText, Ink, notes, stamps, shapes, markup) are drawn from their dictionaries in the page view, page_render and page images, including the CLI render command, never saved; a stamp from another program draws the stamp its /Name names (the fourteen standard names of ISO 32000-2 Table 184, Draft when there is none) or, for any other name, a grey frame with both diagonals; text and choice fields are drawn from their values when the form sets /NeedAppearances (every one) or a widget has no /N (#3470), also display-only and cached per widget (a field edit on a 1000-field /NeedAppearances form takes ~13 ms against ~7 ms on a form that needs none) (a read-only document still gets the renderer's Highlight fallback only); check boxes and radio buttons with no appearance for their /AS are drawn display-only from /MK (background, border, and when on the /MK /CA ZapfDingbats symbol in the /DA colour, a check or a dot by default), and when the form sets /NeedAppearances so is every one that has an /MK, over the appearance the file carries (ISO 32000-2 Table 224; one without /MK keeps its own), and push buttons with none from /MK and /BS with their caption; Link borders without /AP and printing are not covered yet; an annotation of a non-standard type with the Invisible flag (ISO 32000-2 Table 167) is neither drawn nor printed, and a popup's own /AP is never painted on the page (its parent's text shows in the popup window, §12.5.6.14)"
+evidence = ["crates/render/src/raster/tests.rs::widget_appearance_states", "crates/render/src/raster/tests.rs::highlights_without_an_appearance_are_drawn", "crates/engine/src/tests.rs::comments_without_appearances_are_drawn_but_not_saved", "crates/engine/src/tests.rs::cli_display_adds_missing_appearances_without_changing_the_source", "crates/engine/src/tests.rs::fields_left_to_the_viewer_are_displayed_from_their_values", "crates/forms/src/tests.rs::need_appearances_draws_every_text_and_choice_field_in_the_display_copy", "crates/forms/src/tests.rs::the_field_appearance_cache_sees_every_input", "crates/engine/src/tests.rs::buttons_and_combs_left_to_the_viewer_are_displayed", "crates/forms/src/tests.rs::check_boxes_without_an_appearance_show_their_caption_symbol", "crates/forms/src/tests.rs::push_buttons_without_an_appearance_show_their_caption_and_frame", "crates/forms/src/tests.rs::need_appearances_draws_check_boxes_and_radio_buttons_from_their_captions", "crates/engine/src/tests.rs::need_appearances_buttons_are_displayed_from_their_captions", "crates/render/src/raster/tests.rs::invisible_unknown_annotations_and_popups_paint_nothing", "crates/print/src/tests.rs::invisible_annotations_of_unknown_types_do_not_print", "crates/engine/src/tests.rs::stamps_without_appearances_draw_the_stamp_they_name", "crates/automation/tests/it/automation.rs::page_render_draws_stamps_without_an_appearance", "crates/annot/src/tests.rs::a_four_entry_colour_with_a_null_is_cmyk_with_zero", "crates/forms/src/tests.rs::a_four_entry_mk_colour_with_a_null_is_cmyk_with_zero"]
+notes = "comments without /AP (FreeText, Ink, notes, stamps, shapes, markup) are drawn from their dictionaries in the page view, page_render and page images, including the CLI render command, never saved; a four-entry colour with a non-number in it (/C, /IC, /MK /BC and /BG written [1 0 0 null]) is read as CMYK with that entry 0; a stamp from another program draws the stamp its /Name names (the fourteen standard names of ISO 32000-2 Table 184, Draft when there is none) or, for any other name, a grey frame with both diagonals; text and choice fields are drawn from their values when the form sets /NeedAppearances (every one) or a widget has no /N (#3470), also display-only and cached per widget (a field edit on a 1000-field /NeedAppearances form takes ~13 ms against ~7 ms on a form that needs none) (a read-only document still gets the renderer's Highlight fallback only); check boxes and radio buttons with no appearance for their /AS are drawn display-only from /MK (background, border, and when on the /MK /CA ZapfDingbats symbol in the /DA colour, a check or a dot by default), and when the form sets /NeedAppearances so is every one that has an /MK, over the appearance the file carries (ISO 32000-2 Table 224; one without /MK keeps its own), and push buttons with none from /MK and /BS with their caption; Link borders without /AP and printing are not covered yet; an annotation of a non-standard type with the Invisible flag (ISO 32000-2 Table 167) is neither drawn nor printed, and a popup's own /AP is never painted on the page (its parent's text shows in the popup window, §12.5.6.14)"
 
 [[feature]]
 id = "view.render-error-isolation"