Fix #2292: Gracefully handle SQLParseError in SQL formatting

debug_toolbar/panels/sql/utils.py

@@ -93,10 +93,26 @@ def is_select_query(sql):
 
 
 def reformat_sql(sql, *, with_toggle=False):
-    formatted = parse_sql(sql)
+    import logging
+
+    logger = logging.getLogger(__name__)
+
+    # Try to format the full SQL
+    try:
+        formatted = parse_sql(sql)
+    except (sqlparse.exceptions.SQLParseError, RecursionError) as e:
+        logger.warning(f"Failed to format SQL query: {e}")
+        formatted = f"-- SQL formatting failed (query too large)\n{sql}"
+
     if not with_toggle:
         return formatted
-    simplified = parse_sql(sql, simplify=True)
+
+    try:
+        simplified = parse_sql(sql, simplify=True)
+    except (sqlparse.exceptions.SQLParseError, RecursionError) as e:
+        logger.warning(f"Failed to simplify SQL query: {e}")
+        simplified = f"-- Simplified formatting failed\n{sql}"
+
     uncollapsed = f'<span class="djDebugUncollapsed">{simplified}</span>'
     collapsed = f'<span class="djDebugCollapsed djdt-hidden">{formatted}</span>'
     return collapsed + uncollapsed

tests/test_sql_large_query.py

@@ -0,0 +1,42 @@
+import pytest
+
+from debug_toolbar.panels.sql.utils import reformat_sql
+
+
+def test_reformat_sql_with_huge_in_clause():
+    """Test that huge IN clauses don't cause crashes"""
+    # Create a SQL with a huge IN clause (5000 items)
+    items = [f"'{i}'" for i in range(5000)]
+    sql = f"SELECT * FROM table WHERE id IN ({','.join(items)})"
+
+    # This should not raise an exception
+    try:
+        result = reformat_sql(sql, with_toggle=False)
+        assert isinstance(result, str)
+        assert len(result) > 0
+    except Exception as e:
+        pytest.fail(f"reformat_sql raised {type(e).__name__}: {e}")
+
+
+def test_reformat_sql_with_toggle_and_huge_in_clause():
+    """Test with_toggle=True with huge IN clause"""
+    items = [f"'{i}'" for i in range(5000)]
+    sql = f"SELECT * FROM table WHERE id IN ({','.join(items)})"
+
+    try:
+        result = reformat_sql(sql, with_toggle=True)
+        assert isinstance(result, str)
+        assert "djDebugUncollapsed" in result
+        assert "djDebugCollapsed" in result
+    except Exception as e:
+        pytest.fail(f"reformat_sql (with_toggle) raised {type(e).__name__}: {e}")
+
+
+def test_reformat_sql_with_invalid_sql():
+    """Test that invalid SQL is handled gracefully"""
+    sql = "SELECT * FROM WHERE"  # Invalid SQL
+
+    result = reformat_sql(sql, with_toggle=False)
+    assert isinstance(result, str)
+    # Should either contain the SQL or an error message
+    assert len(result) > 0