On Perl 5.17.9, t/apache/read2.t fails because an "uninitialized value"

warning is generated for the buffer being autovivified. This is because
the sv_setpvn() that's meant to vivify the buffer doesn't perform set
magic; the warning is generated by the immediately following SvPV_force().
Patch to fix this from rt.cpan.org #83922. [Zefram]

git-svn-id: https://svn.apache.org/repos/asf/perl/modperl/trunk@1456372 13f79535-47bb-0310-9956-ffa450edef68

Changes

@@ -12,6 +12,12 @@ Also refer to the Apache::Test changes log file, at Apache-Test/Changes
 
 =item 2.0.8-dev
 
+On Perl 5.17.9, t/apache/read2.t fails because an "uninitialized value"
+warning is generated for the buffer being autovivified. This is because
+the sv_setpvn() that's meant to vivify the buffer doesn't perform set
+magic; the warning is generated by the immediately following SvPV_force().
+Patch to fix this from rt.cpan.org #83922. [Zefram]
+
 Fix t/perl/hash_attack.t to work with Perl 5.14.4, 5.16.3 etc, which
 contain a fix for CVE-2013-1667 (memory exhaustion with arbitrary hash
 keys). This resolves rt.perl.org #116863, from where the patch was taken.

xs/Apache2/RequestIO/Apache2__RequestIO.h

@@ -227,6 +227,10 @@ apr_status_t mpxs_setup_client_block(request_rec *r)
 #define mpxs_should_client_block(r) \
     (r->read_length || ap_should_client_block(r))
 
+#ifndef sv_setpvn_mg
+#   define sv_setpvn_mg sv_setpvn
+#endif
+
 /* alias */
 #define mpxs_Apache2__RequestRec_READ(r, buffer, len, offset) \
     mpxs_Apache2__RequestRec_read(aTHX_ r, buffer, len, offset)
@@ -239,7 +243,7 @@ static SV *mpxs_Apache2__RequestRec_read(pTHX_ request_rec *r,
     STRLEN blen;
 
     if (!SvOK(buffer)) {
-        sv_setpvn(buffer, "", 0);
+        sv_setpvn_mg(buffer, "", 0);
     }
 
     (void)SvPV_force(buffer, blen); /* make it a valid PV */