From b5a175c6723e5d670e9decdd7d7be69a3446ab41 Mon Sep 17 00:00:00 2001
From: Arvin Schnell <aschnell@suse.de>
Date: Thu, 26 Nov 2020 09:28:37 +0100
Subject: [PATCH] - use XSI-compliant strerror_r

---
 snapper/AppUtil.cc  | 16 -------------
 snapper/AppUtil2.cc | 55 +++++++++++++++++++++++++++++++++++++++++++++
 snapper/Makefile.am |  1 +
 3 files changed, 56 insertions(+), 16 deletions(-)
 create mode 100644 snapper/AppUtil2.cc

diff --git a/snapper/AppUtil.cc b/snapper/AppUtil.cc
index 1de88ac8..01e4fbcf 100644
--- a/snapper/AppUtil.cc
+++ b/snapper/AppUtil.cc
@@ -220,22 +220,6 @@ namespace snapper
     }
 
 
-    string
-    stringerror(int errnum)
-    {
-#if (_POSIX_C_SOURCE >= 200112L) && ! _GNU_SOURCE
-	char buf1[100];
-	if (strerror_r(errnum, buf1, sizeof(buf1) - 1) == 0)
-	    return string(buf1);
-	return string("strerror failed");
-#else
-	char buf1[100];
-	const char* buf2 = strerror_r(errnum, buf1, sizeof(buf1) - 1);
-	return string(buf2);
-#endif
-    }
-
-
     string
     sformat(const char* format, ...)
     {
diff --git a/snapper/AppUtil2.cc b/snapper/AppUtil2.cc
new file mode 100644
index 00000000..bb6ddc7f
--- /dev/null
+++ b/snapper/AppUtil2.cc
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2020 SUSE LLC
+ *
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, contact Novell, Inc.
+ *
+ * To contact Novell about this file by physical or electronic mail, you may
+ * find current contact information at www.novell.com.
+ */
+
+
+// This tiny file is separated from AppUtil.cc to allow setting specific
+// defines. Unsetting _GNU_SOURCE in AppUtil.cc causes may errors. See
+// https://github.com/openSUSE/snapper/pull/581.
+
+// Defines to get the XSI-compliant strerror_r.
+#define _POSIX_C_SOURCE 200809L
+#undef _GNU_SOURCE
+
+#include <string.h>
+#include <string>
+
+
+namespace snapper
+{
+    using namespace std;
+
+
+    string
+    stringerror(int errnum)
+    {
+	char buf[128];
+
+	// The assignment to int is a safety net that breaks with the GNU version of
+	// strerror_r (which returns char*).
+
+	int r = strerror_r(errnum, buf, sizeof(buf) - 1);
+	if (r != 0)
+	    return string("strerror_r failed");
+
+	return string(buf);
+    }
+
+}
diff --git a/snapper/Makefile.am b/snapper/Makefile.am
index 988b9e32..dced48d7 100644
--- a/snapper/Makefile.am
+++ b/snapper/Makefile.am
@@ -17,6 +17,7 @@ libsnapper_la_SOURCES =					\
 	XmlFile.cc		XmlFile.h		\
 	Enum.cc			Enum.h			\
 	AppUtil.cc		AppUtil.h		\
+	AppUtil2.cc					\
 	FileUtils.cc		FileUtils.h		\
 	XAttributes.cc		XAttributes.h		\
 	Log.cc			Log.h			\
-- 
2.47.3