Actually fix GH #17370

I only added a test, but not the change in
9f16475a53933d1d9c547f871b97b3b12160cece.  The test passes except when
run under address sanitizer or valgrind.

1 files changed, 3 insertions, 0 deletions

diff --git a/numeric.c b/numeric.c
index 142f61753a..0b8677d064 100644
--- a/numeric.c
+++ b/numeric.c
@@ -780,6 +780,9 @@ Perl_grok_infnan(pTHX_ const char** sp, const char* send)
             s++;
 
             flags |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT;
+            if (s == send) {
+                return flags;
+            }
 
             /* NaN can be followed by various stuff (NaNQ, NaNS), but
              * there are also multiple different NaN values, and some