Fix un undefined C behavior in NULL pointer arithmetics

perl-5.29.6-regen-warnings.pl-Fix-undefined-C-behavior.patch

@@ -0,0 +1,83 @@
+From 8c165a32b7cc4f2a147a37c920a96f1b09b2386d Mon Sep 17 00:00:00 2001
+From: Karl Williamson <khw@cpan.org>
+Date: Sun, 30 Dec 2018 21:29:07 -0700
+Subject: [PATCH] regen/warnings.pl: Fix undefined C behavior
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This fixes compiler warnings "performing pointer arithmetic on a null
+pointer has undefined behavior"
+
+There are several ways to fix this.  This one was suggested by
+Tomasz Konojacki++.  Instead of trying to point to address 1 and 2, two
+variables are created, and we point to them.  const is cast away.
+
+Signed-off-by: Petr Písař <ppisar@redhat.com>
+---
+ globvar.sym       | 2 ++
+ perl.h            | 5 +++++
+ regen/warnings.pl | 4 ++--
+ warnings.h        | 4 ++--
+ 4 files changed, 11 insertions(+), 4 deletions(-)
+
+diff --git a/globvar.sym b/globvar.sym
+index 6fb387ca0a..476f4ca095 100644
+--- a/globvar.sym
++++ b/globvar.sym
+@@ -83,4 +83,6 @@ PL_warn_nl
+ PL_warn_nosemi
+ PL_warn_reserved
+ PL_warn_uninit
++PL_WARN_ALL
++PL_WARN_NONE
+ PL_watch_pvx
+diff --git a/perl.h b/perl.h
+index 43b42a8aa5..dd66b120af 100644
+--- a/perl.h
++++ b/perl.h
+@@ -4454,6 +4454,11 @@ EXTCONST char PL_Zero[]
+ EXTCONST char PL_hexdigit[]
+   INIT("0123456789abcdef0123456789ABCDEF");
+ 
++EXTCONST STRLEN PL_WARN_ALL
++  INIT(0);
++EXTCONST STRLEN PL_WARN_NONE
++  INIT(0);
++
+ /* This is constant on most architectures, a global on OS/2 */
+ #ifndef OS2
+ EXTCONST char PL_sh_path[]
+diff --git a/regen/warnings.pl b/regen/warnings.pl
+index 9c01e6762f..d244160b3e 100644
+--- a/regen/warnings.pl
++++ b/regen/warnings.pl
+@@ -322,8 +322,8 @@ my ($index, $warn_size);
+ #define G_WARN_ALL_MASK		(G_WARN_ALL_ON|G_WARN_ALL_OFF)
+ 
+ #define pWARN_STD		NULL
+-#define pWARN_ALL		(((STRLEN*)0)+1)    /* use warnings 'all' */
+-#define pWARN_NONE		(((STRLEN*)0)+2)    /* no  warnings 'all' */
++#define pWARN_ALL		(STRLEN *) &PL_WARN_ALL    /* use warnings 'all' */
++#define pWARN_NONE		(STRLEN *) &PL_WARN_NONE   /* no  warnings 'all' */
+ 
+ #define specialWARN(x)		((x) == pWARN_STD || (x) == pWARN_ALL ||	\
+ 				 (x) == pWARN_NONE)
+diff --git a/warnings.h b/warnings.h
+index e0c12ed403..58f52272de 100644
+--- a/warnings.h
++++ b/warnings.h
+@@ -18,8 +18,8 @@
+ #define G_WARN_ALL_MASK		(G_WARN_ALL_ON|G_WARN_ALL_OFF)
+ 
+ #define pWARN_STD		NULL
+-#define pWARN_ALL		(((STRLEN*)0)+1)    /* use warnings 'all' */
+-#define pWARN_NONE		(((STRLEN*)0)+2)    /* no  warnings 'all' */
++#define pWARN_ALL		(STRLEN *) &PL_WARN_ALL    /* use warnings 'all' */
++#define pWARN_NONE		(STRLEN *) &PL_WARN_NONE   /* no  warnings 'all' */
+ 
+ #define specialWARN(x)		((x) == pWARN_STD || (x) == pWARN_ALL ||	\
+ 				 (x) == pWARN_NONE)
+-- 
+2.17.2
+

perl.spec

@@ -235,6 +235,10 @@ Patch46:        perl-5.29.6-First-eof-should-return-true.patch
 # Fix a crash when compiling a malformed form, RT#132158, in upstream after 5.29.6
 Patch47:        perl-5.29.6-perl-132158-abort-compilation-if-we-see-an-error-com.patch
 
+# Fix un undefined C behavior in NULL pointer arithmetics, RT#133223,
+# in upstream after 5.29.6
+Patch48:        perl-5.29.6-regen-warnings.pl-Fix-undefined-C-behavior.patch
+
 # Link XS modules to libperl.so with EU::CBuilder on Linux, bug #960048
 Patch200:       perl-5.16.3-Link-XS-modules-to-libperl.so-with-EU-CBuilder-on-Li.patch
 
@@ -2836,6 +2840,7 @@ Perl extension for Version Objects
 %patch45 -p1
 %patch46 -p1
 %patch47 -p1
+%patch48 -p1
 %patch200 -p1
 %patch201 -p1
 
@@ -2877,6 +2882,7 @@ perl -x patchlevel.h \
     'Fedora Patch44: Fix reporting a line number for non-terminated prototypes (RT#133524)' \
     'Fedora Patch45: Fix first eof() return value (RT#133721)' \
     'Fedora Patch47: Fix a crash when compiling a malformed form (RT#132158)' \
+    'Fedora Patch48: Fix un undefined C behavior in NULL pointer arithmetics (RT#133223)' \
     'Fedora Patch200: Link XS modules to libperl.so with EU::CBuilder on Linux' \
     'Fedora Patch201: Link XS modules to libperl.so with EU::MM on Linux' \
     %{nil}
@@ -5171,6 +5177,7 @@ popd
 - Fix reporting a line number for non-terminated prototypes (RT#133524)
 - Fix first eof() return value (RT#133721)
 - Fix a crash when compiling a malformed form (RT#132158)
+- Fix un undefined C behavior in NULL pointer arithmetics (RT#133223)
 
 * Mon Jan 14 2019 Björn Esser <besser82@fedoraproject.org> - 4:5.28.1-429
 - Rebuilt for libcrypt.so.2 (#1666033)