#3205: bz2 iterator fails silently on MemoryError

(backport from r65609)

Misc/NEWS

@@ -145,6 +145,9 @@ Library
 Extension Modules
 -----------------
 
+- Issue #3205: When iterating over a BZ2File fails allocating memory, raise
+  a MemoryError rather than silently stop the iteration.
+
 - Patch #2111: Avoid mmap segfault when modifying a PROT_READ block.
 
 - zlib.decompressobj().flush(value) no longer crashes the interpreter when

Modules/bz2module.c

@@ -416,6 +416,7 @@ Util_ReadAhead(BZ2FileObject *f, int bufsize)
 		return 0;
 	}
 	if ((f->f_buf = PyMem_Malloc(bufsize)) == NULL) {
+		PyErr_NoMemory();
 		return -1;
 	}
 	Py_BEGIN_ALLOW_THREADS