Fix broken fix for RT #127212

As ilmari++ points out, the fix didn't work on builds without
PERL_IMPLICIT_CONTEXT (including non-threaded, non-multiplicity) or
PERL_DEBUG_READONLY_COW.

diff --git a/intrpvar.h b/intrpvar.h
index 64a0e6b..090bc58 100644 (file)
--- a/intrpvar.h
+++ b/intrpvar.h
@@ -780,11 +780,13 @@ PERLVARI(I, my_cxt_keys, const char **, NULL) /* per-module array of pointers to
 #  endif
 #endif
 
+#if defined(PERL_IMPLICIT_CONTEXT) || defined(PERL_DEBUG_READONLY_COW)
 /* For use with the memory debugging code in util.c. This is used only in
- * DEBUGGING builds, but defining it in non-debug builds too means that we
- * retain binary compatibility between otherwise-compatible plain and debug
- * builds. */
+ * DEBUGGING builds (as long as the relevant structure is defined), but
+ * defining it in non-debug builds too means that we retain binary
+ * compatibility between otherwise-compatible plain and debug builds. */
 PERLVAR(I, memory_debug_header, struct perl_memory_debug_header)
+#endif
 
 #ifdef DEBUG_LEAKING_SCALARS_FORK_DUMP
 /* File descriptor to talk to the child which dumps scalars.  */