Add an auto-generated unicode character category file

[TheBlueMatt]

1a01b5a added detection of unicode format characters in PrintableString, but used a hard-coded table which may eventually become out of date.

Here we switch to an auto-generated table, include all General_Category Other characters, and also ban unallocated code points.

Finally, CI validates that the file is kept up to date.

Written by Claude

[ldk-reviews-bot]

👋 Thanks for assigning @tnull as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

[ldk-claude-review-bot]

Nit: c.is_control() is now fully redundant — it checks Cc (Control), which is already covered by is_unicode_general_category_other (see 0x0000..=0x001F and 0x007F..=0x009F in unicode.rs). The old code needed it because is_format_char only covered Cf, but the new function covers all of Cc / Cf / Cs / Co.

Not a bug (the || short-circuits harmlessly), but it's potentially confusing because it suggests is_other doesn't handle control characters.

Suggested change

	let is_other = is_unicode_general_category_other(c);
	let is_unassigned = is_unicode_general_category_unassigned(c);
	let c = if c.is_control() || is_other || is_unassigned {
	let c = if is_unicode_general_category_other(c) || is_unicode_general_category_unassigned(c) {

[ldk-claude-review-bot]

Review Summary

New issue found

• .github/workflows/check_unicode.yml:25 — gh issue create runs without deduplication; will create a new issue every day the file is out of date. build.yml already demonstrates the correct pattern (check for existing open issue, comment on it instead).

Correction to prior review

My three prior comments about the YAML workflow file (missing jobs: key, missing checkout step, fi indentation) were incorrect — the file structure is fine as written. I misread the diff indentation. Apologies for the noise.

Prior comment still applicable

• lightning-types/src/string.rs:38 — c.is_control() remains redundant with is_unicode_general_category_other, which already covers all Cc characters.

[codecov]

Codecov Report

❌ Patch coverage is 92.23301% with 40 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.15%. Comparing base (1a01b5a) to head (65e8cc8).
⚠️ Report is 66 commits behind head on main.

Files with missing lines	Patch %	Lines
lightning-types/src/unicode.rs	92.18%	40 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4605      +/-   ##
==========================================
+ Coverage   86.09%   86.15%   +0.06%     
==========================================
  Files         157      158       +1     
  Lines      108828   109323     +495     
  Branches   108828   109323     +495     
==========================================
+ Hits        93694    94189     +495     
+ Misses      12519    12518       -1     
- Partials     2615     2616       +1     

Flag	Coverage Δ
tests	86.15% <92.23%> (+0.06%)	⬆️

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[tnull]

Alright, seems maybe a bit excessive, but fine by me. No need to check this on every CI run though, let's just move it to a weekly cronjob?

[tnull]

Looks good, please squash.

[tnull]

Claude's reviews seem legit though

[TheBlueMatt]

Squashed and fixed claude's comments:

$ git diff-tree -U2 2de5954d9 65e8cc8d5
diff --git a/.github/workflows/check_unicode.yml b/.github/workflows/check_unicode.yml
index c22a4e3b29..a01add3f81 100644
--- a/.github/workflows/check_unicode.yml
+++ b/.github/workflows/check_unicode.yml
@@ -5,4 +5,5 @@ on:
     - cron: '42 3 * * *'

+jobs:
   check-unicode:
     runs-on: ubuntu-latest
@@ -10,4 +11,6 @@ on:
       issues: write
     steps:
+      - name: Checkout source code
+        uses: actions/checkout@v4
       - name: Check unicode file state
         env:
@@ -21,3 +24,3 @@ on:
             BODY="The unicode character listing is out of date, see $RUN_URL"
             gh issue create --title "$TITLE" --body "$BODY"
-        fi
+          fi

[ldk-claude-review-bot]

Bug: No deduplication — this creates a new issue every day the file is out of date. Unicode updates are infrequent (roughly annual), but if nobody regenerates the file promptly, this will spam the issue tracker with identical issues.

build.yml already has the right pattern (lines 380-391): check for an existing open issue with a label, and comment on it instead of creating a duplicate. This workflow should do the same.

Minimal fix sketch:

          LABEL="unicode outdated"
          gh label create "$LABEL" 2>/dev/null || true
          EXISTING=$(gh issue list --label "$LABEL" --state open --json number --jq '.[0].number // empty')
          if [ -n "$EXISTING" ]; then
            gh issue comment "$EXISTING" --body "$BODY"
          else
            gh issue create --title "$TITLE" --label "$LABEL" --body "$BODY"
          fi

[TheBlueMatt]

Eh, that takes effort, this is fine we expect to respond quickly.

[TheBlueMatt]

Backported to 0.1 in #4680.

[TheBlueMatt]

Backported to 0.2 in #4683.