gh-125843: indicate which C function caused a `curses.error` (#125844)

- Rename error helpers with a `curses_set_error_*` prefix instead of `PyCurses*`.
- Cleanly report both NULL and ERR cases.
- Raise `curses.error` in `is_linetouched` instead of a `TypeError`.

Include/py_curses.h

@@ -109,6 +109,13 @@ static void **PyCurses_API;
 static const char catchall_ERR[]  = "curses function returned ERR";
 static const char catchall_NULL[] = "curses function returned NULL";
 
+#if defined(CURSES_MODULE) || defined(CURSES_PANEL_MODULE)
+/* Error messages shared by the curses package */
+#  define CURSES_ERROR_FORMAT           "%s() returned %s"
+#  define CURSES_ERROR_VERBOSE_FORMAT   "%s() (called by %s()) returned %s"
+#  define CURSES_ERROR_MUST_CALL_FORMAT "must call %s() first"
+#endif
+
 #ifdef __cplusplus
 }
 #endif

Lib/test/test_curses.py

@@ -130,6 +130,9 @@ def test_use_env(self):
         curses.use_env(False)
         curses.use_env(True)
 
+    def test_error(self):
+        self.assertIsSubclass(curses.error, Exception)
+
     def test_create_windows(self):
         win = curses.newwin(5, 10)
         self.assertEqual(win.getbegyx(), (0, 0))

Misc/NEWS.d/next/Library/2024-10-22-16-21-55.gh-issue-125843.2ttzYo.rst

@@ -0,0 +1,2 @@
+If possible, indicate which :mod:`curses` C function or macro is responsible
+for raising a :exc:`curses.error` exception. Patch by Bénédikt Tran.