[3.12] gh-120155: Add assertion to sre.c match_getindex() (GH-120402) (#120410)

gh-120155: Add assertion to sre.c match_getindex() (GH-120402)

Add an assertion to help static analyzers to detect that i*2 cannot
overflow.
(cherry picked from commit 42b25dd61ff3593795c4cc2ffe876ab766098b24)

Co-authored-by: Victor Stinner <vstinner@python.org>

diff --git a/Modules/_sre/sre.c b/Modules/_sre/sre.c
index 8ef35d0658c703e77d2ebd79c2a4aff6039c990b..6d9843bb76d7918f6e23d4e521530affc4ea3d61 100644 (file)
--- a/Modules/_sre/sre.c
+++ b/Modules/_sre/sre.c
@@ -2167,6 +2167,8 @@ match_getindex(MatchObject* self, PyObject* index)
         return -1;
     }
 
+    // Check that i*2 cannot overflow to make static analyzers happy
+    assert(i <= SRE_MAXGROUPS);
     return i;
 }