bpo-32591: Fix PyExc_WarnFormat call (follow-up commit) (#5263)

1st1 · web-flow · commit 3510334361d6 · 2018-01-21T20:47:04.000-05:00
The previous version was correct in terms of behaviour, but
checking the return value of PyErr_WarnFormat allows to
avoid calling PyErr_Occurred and silences the coverity alarm.
diff --git a/Python/_warnings.c b/Python/_warnings.c
@@ -1191,11 +1191,10 @@ _PyErr_WarnUnawaitedCoroutine(PyObject *coro)
         PyErr_WriteUnraisable(coro);
     }
     if (!warned) {
-        PyErr_WarnFormat(PyExc_RuntimeWarning, 1,
-                         "coroutine '%.50S' was never awaited",
-                         ((PyCoroObject *)coro)->cr_qualname);
-        /* Maybe *that* got converted into an exception */
-        if (PyErr_Occurred()) {
+        if (PyErr_WarnFormat(PyExc_RuntimeWarning, 1,
+                             "coroutine '%.50S' was never awaited",
+                             ((PyCoroObject *)coro)->cr_qualname) < 0)
+        {
             PyErr_WriteUnraisable(coro);
         }
     }

Original file line number	Diff line number	Diff line change
`@@ -1191,11 +1191,10 @@ _PyErr_WarnUnawaitedCoroutine(PyObject *coro)`
`1191`	`1191`	`PyErr_WriteUnraisable(coro);`
`1192`	`1192`	`}`
`1193`	`1193`	`if (!warned) {`
`1194`		`- PyErr_WarnFormat(PyExc_RuntimeWarning, 1,`
`1195`		`- "coroutine '%.50S' was never awaited",`
`1196`		`- ((PyCoroObject *)coro)->cr_qualname);`
`1197`		`- /* Maybe that got converted into an exception */`
`1198`		`- if (PyErr_Occurred()) {`
	`1194`	`+ if (PyErr_WarnFormat(PyExc_RuntimeWarning, 1,`
	`1195`	`+ "coroutine '%.50S' was never awaited",`
	`1196`	`+ ((PyCoroObject *)coro)->cr_qualname) < 0)`
	`1197`	`+ {`
`1199`	`1198`	`PyErr_WriteUnraisable(coro);`
`1200`	`1199`	`}`
`1201`	`1200`	`}`