Integrate maintperl changes #12268 and #12669;

final touches to the audit for statics and thread-unsafe code
* make DB_File, ODBM_File thread-safe 
* remove unnecessary/dangerous statics and protect others
  from not getting accidentally enabled under threaded perls

windows support functions get_childdir() et al aren't exported
correctly under vanilla build

Testing under win32 appreciated since changes there had
to be manually merged and I cannot test how badly did I do.

p4raw-link: @12268 on //depot/perlio: bb407f0b8769c638c05e60ebfd157a1e676a6c22

p4raw-id: //depot/perl@12678
p4raw-integrated: from //depot/maint-5.6/perl@12677 'copy in'
	win32/vmem.h (@5902..) 'merge in' ext/DB_File/DB_File.xs
	(@8693..) win32/win32iop.h (@8917..) ext/ODBM_File/ODBM_File.xs
	(@8995..) iperlsys.h (@9154..) scope.c (@9584..) makedef.pl
	(@11425..) gv.c (@12026..) op.c (@12145..) util.c (@12220..)
	toke.c (@12550..) ext/B/B.xs ext/File/Glob/Glob.xs
	ext/Opcode/Opcode.xs ext/re/re.xs (@12653..) mg.c win32/win32.c
	(@12668..)

1 files changed, 9 insertions, 21 deletions

diff --git a/mg.c b/mg.c
index 4e186e0c5f..9b91777631 100644
--- a/mg.c
+++ b/mg.c
@@ -959,27 +959,10 @@ Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
 #if defined(VMS) || defined(EPOC)
     Perl_die(aTHX_ "Can't make list assignment to %%ENV on this system");
 #else
-#   ifdef PERL_IMPLICIT_SYS
+#   if defined(PERL_IMPLICIT_SYS) || defined(WIN32)
     PerlEnv_clearenv();
 #   else
-#	ifdef WIN32
-    char *envv = GetEnvironmentStrings();
-    char *cur = envv;
-    STRLEN len;
-    while (*cur) {
-	char *end = strchr(cur,'=');
-	if (end && end != cur) {
-	    *end = '\0';
-	    my_setenv(cur,Nullch);
-	    *end = '=';
-	    cur = end + strlen(end+1)+2;
-	}
-	else if ((len = strlen(cur)))
-	    cur += len+1;
-    }
-    FreeEnvironmentStrings(envv);
-#	else
-#ifdef USE_ENVIRON_ARRAY
+#if !defined(MACOS_TRADITIONAL)
 #	    ifndef PERL_USE_SAFE_PUTENV
     I32 i;
 
@@ -992,8 +975,7 @@ Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
 
     environ[0] = Nullch;
 
-#endif /* USE_ENVIRON_ARRAY */
-#	endif /* WIN32 */
+#endif /* !defined(MACOS_TRADITIONAL) */
 #   endif /* PERL_IMPLICIT_SYS */
 #endif /* VMS */
     return 0;
@@ -2222,7 +2204,9 @@ Perl_whichsig(pTHX_ char *sig)
     return 0;
 }
 
+#if !defined(PERL_IMPLICIT_CONTEXT)
 static SV* sig_sv;
+#endif
 
 Signal_t
 Perl_sighandler(int sig)
@@ -2290,7 +2274,9 @@ Perl_sighandler(int sig)
     if(PL_psig_name[sig]) {
     	sv = SvREFCNT_inc(PL_psig_name[sig]);
 	flags |= 64;
+#if !defined(PERL_IMPLICIT_CONTEXT)
 	sig_sv = sv;
+#endif
     } else {
 	sv = sv_newmortal();
 	sv_setpv(sv,PL_sig_name[sig]);
@@ -2391,6 +2377,8 @@ unwind_handler_stack(pTHX_ void *p)
     if (flags & 1)
 	PL_savestack_ix -= 5; /* Unprotect save in progress. */
     /* cxstack_ix-- Not needed, die already unwound it. */
+#if !defined(PERL_IMPLICIT_CONTEXT)
     if (flags & 64)
 	SvREFCNT_dec(sig_sv);
+#endif
 }