fix(docx): one bookmark per anchor, no control characters, and margins below zero written

CHANGELOG.md

@@ -8,6 +8,24 @@ follow semantic versioning; release dates are ISO 8601.
 
 ### Public API
 
+- **A DOCX export keeps each anchor's bookmark its own, writes no control character the page
+  draws nothing for, sets a margin below zero out past its side, and says what a rounded panel
+  keeps.** A bookmark name a suffix made for one anchor — "Section-1" after "Section 1" took
+  `Section_1_2` — was given again to the anchor that cleans to it, "Section 1 2", so two links
+  went to one place; a name is now taken only once it is free. An anchor two nodes declare was a
+  bookmark on each, one name twice, where Word goes to the first and the page to the last: the
+  file now keeps the last it writes, and the report names the anchor — where the page's last is
+  a node the file writes no bookmark for too. A character the page leaves out — a control (a
+  bell, a null, a tab), a soft hyphen, a zero-width space, one of private use — was written, the
+  controls mostly as a question mark ("Total? due"), in runs, headers and footers, a badge's
+  initials, a list's marker and a picture's or a barcode's description; it is now left out too,
+  the line breaks and the direction marks and joiners kept. A margin below zero on a paragraph or
+  a list, and on the right of a block round them, was written as none, the text at the margin
+  where the page set it out past it; it is now an indent below zero in the flow. In a table
+  cell, a panel's included, the text stands as far out as the cell's text and no further, what
+  is held back named; a row's first child the page sets out past the row's left edge starts at
+  it, named. The corner-radius note on a rounded panel said it kept its fill where it had only a
+  border; it now says which it keeps.
 - **A DOCX export writes a page zone the page builds otherwise for the first page into the
   first page's header or footer.** Word paginates, so a zone's content was built once, for a
   page that was both the first and the last, and written on every page: a footer reading

render-docx/src/main/java/com/demcha/compose/document/backend/semantic/docx/DocxBookmarkNames.java

@@ -1,8 +1,10 @@
 package com.demcha.compose.document.backend.semantic.docx;
 
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * The name Word will accept for one of the document's own anchors.
@@ -29,6 +31,8 @@ final class DocxBookmarkNames {
 
     private final Map<String, String> byAnchor = new HashMap<>();
     private final Map<String, Integer> collisions = new HashMap<>();
+    /** Every name given, without case. */
+    private final Set<String> taken = new HashSet<>();
     private int nextId;
 
     /**
@@ -72,16 +76,24 @@ private String mint(String anchor) {
 
         // Two anchors that clean to the same text are still two anchors. Without this the
         // second one's bookmark would sit on the first one's name and every link to either
-        // would land in the same place.
+        // would land in the same place. A name a suffix makes is another anchor's own too:
+        // "Section-1" became "Section_1_2", which "Section 1 2" cleans to, so a name is taken
+        // only once it is free. Word reads bookmark names without case.
         String key = base.toLowerCase(Locale.ROOT);
         int seen = collisions.merge(key, 1, Integer::sum);
-        if (seen == 1) {
-            return base;
+        // The n-th anchor of a name is tried as name_n first, the first as the name itself.
+        int number = Math.max(seen, 2) - 1;
+        String name = seen == 1 ? base : suffixed(base, ++number);
+        while (!taken.add(name.toLowerCase(Locale.ROOT))) {
+            name = suffixed(base, ++number);
         }
-        String suffix = "_" + seen;
-        String trimmed = base.length() + suffix.length() > MAX_LENGTH
-                ? base.substring(0, MAX_LENGTH - suffix.length())
-                : base;
-        return trimmed + suffix;
+        return name;
+    }
+
+    /** A name with a number after it, cut to fit Word's length. */
+    private static String suffixed(String base, int number) {
+        String suffix = "_" + number;
+        return (base.length() + suffix.length() > MAX_LENGTH ? base.substring(0, MAX_LENGTH - suffix.length()) : base)
+               + suffix;
     }
 }

render-docx/src/main/java/com/demcha/compose/document/backend/semantic/docx/DocxLayoutMetrics.java

@@ -636,6 +636,31 @@ private Map<String, PlacedFragment> zoneFragments(int zoneIndex, int page,
         return found;
     }
 
+    /**
+     * How many nodes declare each anchor the layout registers: the page sends a link to the last.
+     * A node a repeated table header draws again is one node; a page zone's, for which the file
+     * holds no bookmark, is left out.
+     *
+     * @return each anchor's count of declaring nodes, empty without a layout
+     */
+    Map<String, Integer> anchorsDeclared() {
+        Map<String, java.util.Set<String>> nodes = new HashMap<>();
+        for (Map.Entry<String, List<PlacedFragment>> entry : fragments.entrySet()) {
+            if (entry.getKey().startsWith("@page-zone")) {
+                continue;
+            }
+            for (PlacedFragment fragment : entry.getValue()) {
+                if (fragment.payload() instanceof com.demcha.compose.document.layout.payloads.AnchorMarkerPayload marker
+                    && !marker.anchor().isEmpty()) {
+                    nodes.computeIfAbsent(marker.anchor(), key -> new java.util.HashSet<>()).add(entry.getKey());
+                }
+            }
+        }
+        Map<String, Integer> counts = new HashMap<>();
+        nodes.forEach((anchor, declaring) -> counts.put(anchor, declaring.size()));
+        return counts;
+    }
+
     /**
      * The first page a page zone is drawn on.
      *