Fix a couple of typos.

[p5sagit/p5-mst-13.2.git] / mg.c

diff --git a/mg.c b/mg.c
index 0feb7da..b5a9290 100644 (file)
--- a/mg.c
+++ b/mg.c
@@ -15,6 +15,24 @@
 
 /*
 =head1 Magical Functions
+
+"Magic" is special data attached to SV structures in order to give them
+"magical" properties.  When any Perl code tries to read from, or assign to,
+an SV marked as magical, it calls the 'get' or 'set' function associated
+with that SV's magic. A get is called prior to reading an SV, in order to
+give it a chance to update its internal value (get on $. writes the line
+number of the last read filehandle into to the SV's IV slot), while
+set is called after an SV has been written to, in order to allow it to make
+use of its changed value (set on $/ copies the SV's new value to the
+PL_rs global variable).
+
+Magic is implemented as a linked list of MAGIC structures attached to the
+SV. Each MAGIC struct holds the type of the magic, a pointer to an array
+of functions that implement the get(), set(), length() etc functions,
+plus space for some flags and pointers. For example, a tied variable has
+a MAGIC structure that contains a pointer to the object associated with the
+tie.
+
 */
 
 #include "EXTERN.h"
@@ -677,7 +695,7 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
     case '\023':               /* ^S */
         if (*(mg->mg_ptr+1) == '\0') {
            if (PL_lex_state != LEX_NOTPARSING)
-               (void)SvOK_off(sv);
+               SvOK_off(sv);
            else if (PL_in_eval)
                sv_setiv(sv, PL_in_eval & ~(EVAL_INREQUIRE));
            else
@@ -1064,6 +1082,7 @@ Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
 #      endif
     {
 #      ifndef PERL_USE_SAFE_PUTENV
+    if (!PL_use_safe_putenv) {
     I32 i;
 
     if (environ == PL_origenviron)
@@ -1071,6 +1090,7 @@ Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
     else
        for (i = 0; environ[i]; i++)
            safesysfree(environ[i]);
+    }
 #      endif /* PERL_USE_SAFE_PUTENV */
 
     environ[0] = Nullch;
@@ -1670,7 +1690,7 @@ Perl_magic_getpos(pTHX_ SV *sv, MAGIC *mg)
            return 0;
        }
     }
-    (void)SvOK_off(sv);
+    SvOK_off(sv);
     return 0;
 }
 
@@ -1843,7 +1863,7 @@ Perl_magic_getvec(pTHX_ SV *sv, MAGIC *mg)
     SV *lsv = LvTARG(sv);
 
     if (!lsv) {
-       (void)SvOK_off(sv);
+       SvOK_off(sv);
        return 0;
     }
 
@@ -1950,7 +1970,7 @@ Perl_magic_killbackrefs(pTHX_ SV *sv, MAGIC *mg)
                Perl_croak(aTHX_ "panic: magic_killbackrefs");
            /* XXX Should we check that it hasn't changed? */
            SvRV(svp[i]) = 0;
-           (void)SvOK_off(svp[i]);
+           SvOK_off(svp[i]);
            SvWEAKREF_off(svp[i]);
            svp[i] = Nullsv;
        }
@@ -2053,7 +2073,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
     case '\004':       /* ^D */
 #ifdef DEBUGGING
        s = SvPV_nolen(sv);
-       PL_debug = get_debug_opts(&s) | DEBUG_TOP_FLAG;
+       PL_debug = get_debug_opts(&s, 0) | DEBUG_TOP_FLAG;
        DEBUG_x(dump_all());
 #else
        PL_debug = (SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv)) | DEBUG_TOP_FLAG;