use cBOOL for bool casts

bool b = (bool)some_int

doesn't necessarily do what you think. In some builds, bool is defined as
char, and that cast's behaviour is thus undefined. So this line in mg.c:

    const bool was_temp = (bool)SvTEMP(sv);

was actually setting was_temp to false even when the SVs_TEMP flag was set.
Fix this by replacing all the (bool) casts with a new cBOOL() cast macro
that (hopefully) does the right thing.

1 files changed, 2 insertions, 2 deletions

diff --git a/mg.c b/mg.c
index 3fb8ec43f4..4a8d7673a5 100644
--- a/mg.c
+++ b/mg.c
@@ -193,7 +193,7 @@ Perl_mg_get(pTHX_ SV *sv)
 {
     dVAR;
     const I32 mgs_ix = SSNEW(sizeof(MGS));
-    const bool was_temp = (bool)SvTEMP(sv);
+    const bool was_temp = cBOOL(SvTEMP(sv));
     bool have_new = 0;
     MAGIC *newmg, *head, *cur, *mg;
     /* guard against sv having being freed midway by holding a private
@@ -2359,7 +2359,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	sv_setsv(PL_bodytarget, sv);
 	break;
     case '\003':	/* ^C */
-	PL_minus_c = (bool)SvIV(sv);
+	PL_minus_c = cBOOL(SvIV(sv));
 	break;
 
     case '\004':	/* ^D */