fix: decode   to a non-breaking space so blank paragraphs survive trimming

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

crates/engine/src/cmd/richclip.rs

@@ -313,7 +313,7 @@ fn decode_text(raw: &str) -> String {
             "gt" => Some('>'),
             "quot" => Some('"'),
             "apos" => Some('\''),
-            "nbsp" => Some(' '),
+            "nbsp" => Some('\u{a0}'),
             _ => entity.strip_prefix('#').and_then(numeric_char),
         };
         if let Some(c) = decoded {

crates/engine/src/tests.rs

@@ -268,6 +268,30 @@ fn html_paste_with_a_source_newline_keeps_its_bold() {
     assert_eq!(body.paragraphs[0].runs[0].props.bold, Some(true), "{body:?}");
 }
 
+#[test]
+fn html_paste_keeps_a_blank_nbsp_paragraph_and_the_rich_path() {
+    for blank in ["<p>&nbsp;</p>", "<p><o:p>&nbsp;</o:p></p>"] {
+        let mut s = session();
+        let html = format!("<p><b>A</b></p>{blank}<p>B</p>");
+        s.execute("edit.paste", &json!({"text": "A\n\u{a0}\nB", "html": html})).unwrap();
+        let body = s
+            .doc()
+            .unwrap()
+            .current_slide()
+            .unwrap()
+            .shapes
+            .iter()
+            .find(|sh| sh.text.as_ref().is_some_and(|t| t.paragraphs.len() == 3))
+            .unwrap()
+            .text
+            .clone()
+            .unwrap();
+        assert_eq!(body.paragraphs[0].runs[0].text, "A", "{html}: {body:?}");
+        assert_eq!(body.paragraphs[0].runs[0].props.bold, Some(true), "{html}: {body:?}");
+        assert_eq!(body.paragraphs[2].runs[0].text, "B", "{html}: {body:?}");
+    }
+}
+
 #[test]
 fn group_ungroup_roundtrip_positions() {
     let mut s = session();