Keep mid-field quotes when splitting with Text to Columns (#2438)

Found while testing crates/engine/src/cmd/data.rs:992 (split_delimited, used by text_to_columns)

Co-authored-by: Claude Haiku 5.5 <noreply@anthropic.com>

crates/engine/src/cmd/data/tools.rs

@@ -183,8 +183,11 @@ pub(super) fn split_delimited(text: &str, delims: &[char], consecutive: bool, qu
     let mut in_q = false;
     let mut last_delim = false;
     let mut chars = text.chars().peekable();
+    let mut at_start = true;
     while let Some(c) = chars.next() {
-        if c == quote {
+        if c == quote && (in_q || at_start) {
+            at_start = false;
+            last_delim = false;
             if in_q && chars.peek() == Some(&quote) {
                 cur.push(quote);
                 chars.next();
@@ -199,9 +202,11 @@ pub(super) fn split_delimited(text: &str, delims: &[char], consecutive: bool, qu
             }
             out.push(std::mem::take(&mut cur));
             last_delim = true;
+            at_start = true;
             continue;
         }
         last_delim = false;
+        at_start = false;
         cur.push(c);
     }
     out.push(cur);

crates/engine/src/tests.rs

@@ -6378,6 +6378,16 @@ mod objects;
 mod python_cells;
 mod python_commands;
 mod python_files;
+
+#[test]
+fn text_to_columns_keeps_a_mid_field_quote() {
+    let mut s = s();
+    s.execute("cell.set", json!({"cell": "A1", "input": "'5\" pipe,abc"})).unwrap();
+    s.execute("data.textToColumns", json!({"range": "A1", "delimiters": [","]})).unwrap();
+    assert_eq!(v(&s, "A1"), Value::text("5\" pipe"));
+    assert_eq!(v(&s, "B1"), Value::text("abc"));
+}
+
 mod seams;
 
 #[test]

crates/engine/src/tests/python_cells.rs

@@ -175,8 +175,8 @@ fn text_to_columns_keeps_a_py_piece_as_text() {
     s.execute("cell.set", json!({"cell": "A1", "input": "'=PY(\"x\");7"})).unwrap();
     assert_eq!(super::v(&s, "A1"), Value::text("=PY(\"x\");7"));
     s.execute("data.textToColumns", json!({"range": "A1", "delimiters": [";"]})).unwrap();
-    // The default text qualifier takes the quotes away, as in Excel.
-    assert_eq!(super::v(&s, "A1"), Value::text("=PY(x)"), "the piece is kept, not cleared");
+    // A quote in the middle of a field is kept, as in Excel.
+    assert_eq!(super::v(&s, "A1"), Value::text("=PY(\"x\")"), "the piece is kept, not cleared");
     assert_eq!(code(&s, 0, "A1"), None, "and it is not a Python cell");
     assert_eq!(super::v(&s, "B1"), Value::Number(7.0));
 }