Prevent endless loop with buttons (#1626)

* fix: prevent endless loop with buttons

* test: added test for add w/o max width

* docs: added changelog record

* chore: explicit set max_width 0

CHANGES/1595.bugfix.rst

@@ -0,0 +1 @@
+Fixed endless loop while adding buttons to the :code:`KeyboardBuilder`.

aiogram/utils/keyboard.py

@@ -179,9 +179,12 @@ class KeyboardBuilder(Generic[ButtonType], ABC):
             last_row.extend(head)
 
         # Separate buttons to exclusive rows with max possible row width
-        while buttons:
-            row, buttons = buttons[: self.max_width], buttons[self.max_width :]
-            markup.append(list(row))
+        if self.max_width > 0:
+            while buttons:
+                row, buttons = buttons[: self.max_width], buttons[self.max_width :]
+                markup.append(list(row))
+        else:
+            markup.append(list(buttons))
 
         self._markup = markup
         return self

tests/test_utils/test_keyboard.py

@@ -170,6 +170,16 @@ class TestKeyboardBuilder:
         if last_columns:
             assert len(markup[-1]) == last_columns
 
+    def test_add_wo_max_width(self):
+        builder = KeyboardBuilder(button_type=KeyboardButton)
+        builder.max_width = 0
+        count = 42
+
+        for index in range(count):
+            builder.add(KeyboardButton(text=f"btn-{index}"))
+
+        assert len(list(builder.buttons)) == count
+
     def test_row(
         self,
     ):