Closes#1618 (reported by @Zixim) and corrects #1463's previous fix.
Bug: YAML, JSON, and diff/patch fenced code blocks render flattened to a
single line. Reporter noted the bug persisted v0.50.279 -> v0.50.291 ->
v0.50.292 despite PR #1516's CSS-only "fix".
Root cause: PR #484 (v0.50.237) added a JSON/YAML tree-viewer that routes
those languages through <div class="code-tree-wrap">...<pre class="tree-raw-view">
instead of bare <pre>. Same release added the diff/patch coloring path
that emits <pre class="diff-block">. The _pre_stash regex at
static/ui.js:1914 matched only literal <pre> with no attributes:
<pre>[\s\S]*?<\/pre>
Both new shapes failed to match, fell through to the paragraph-wrap pass,
and \n characters inside the code blocks got replaced with <br> tags
inside <code>. By the time Prism ran, no newlines remained for the CSS
rule (PR #1516, language-yaml .token { white-space: pre !important }) to
preserve.
Fix: relax the regex to accept any attribute on <pre>:
<pre>[\s\S]*?<\/pre> -> <pre[^>]*>[\s\S]*?<\/pre>
One regex character. Pulls JSON, YAML, and diff/patch blocks into the
stash so paragraph-wrap can't mangle them. Bash, Python, Go, etc. were
never affected because they emit bare <pre>.
Tests: 9 new (2 source-string invariants + 7 behavioural via node-driver
against the actual static/ui.js renderMd()). 6 of the 7 behavioural tests
fail on master and pass with the fix; the 3 sanity checks (yml-alias,
bash, mermaid) pass on both.
Plus widened source-scan window in 3 pre-existing test_745 assertions
from 400 to 1500 chars. The new comment block above the fixed regex
pushed it past the previous scan window. Pure window-narrowness bug,
not a behavior regression.
4245 -> 4254 passing.