Avoid duplicate "/etc/krb5.conf" in profile path

If configure gets run with --sysconfdir=/etc, "/etc/krb5.conf" shows
up twice in the profile path, which causes its contents to be read
twice.  This can cause some confusing and possibly problematic
behavior.

Add some logic to configure.in to avoid adding the duplicate entry for
"/etc/krb5.conf".

Reported independently by Denis Vlasenko and Fredrik Tolf.

(back ported from commit 8df1965)
(cherry picked from commit 51ef4b5)

ticket: 8084 (new)
version_fixed: 1.11.6
status: resolved

src/configure.in

@@ -1,5 +1,14 @@
 K5_AC_INIT([aclocal.m4])
 
+# Don't make duplicate profile path entries for /etc/krb5.conf if
+# $sysconfdir is /etc
+if test "$sysconfdir" == /etc; then
+  SYSCONFCONF=""
+else
+  SYSCONFCONF=":${sysconfdir}/krb5.conf"
+fi
+AC_SUBST(SYSCONFCONF)
+
 CONFIG_RULES
 KRB5_VERSION=K5_VERSION
 AC_SUBST(KRB5_VERSION)

src/include/Makefile.in

@@ -56,6 +56,7 @@ LOCALSTATEDIR = @localstatedir@
 BINDIR = @bindir@
 SBINDIR = @sbindir@
 LIBDIR  = @libdir@
+SYSCONFCONF = @SYSCONFCONF@
 
 PROCESS_REPLACE = -e "s+@KRB5RCTMPDIR+$(KRB5RCTMPDIR)+" \
 		  -e "s+@PREFIX+$(INSTALL_PREFIX)+" \
@@ -67,7 +68,8 @@ PROCESS_REPLACE = -e "s+@KRB5RCTMPDIR+$(KRB5RCTMPDIR)+" \
 		  -e "s+@GSSMODULEDIR+$(GSS_MODULE_DIR)+" \
 		  -e 's+@LOCALSTATEDIR+$(LOCALSTATEDIR)+' \
 		  -e 's+@SYSCONFDIR+$(SYSCONFDIR)+' \
-		  -e 's+@DYNOBJEXT+$(DYNOBJEXT)+'
+		  -e 's+@DYNOBJEXT+$(DYNOBJEXT)+' \
+		  -e 's+@SYSCONFCONF+$(SYSCONFCONF)+'
 
 OSCONFSRC = $(srcdir)/osconf.hin
 

src/include/osconf.hin

@@ -44,13 +44,13 @@
 #define DEFAULT_PROFILE_FILENAME "krb5.ini"
 #else /* !_WINDOWS */
 #if TARGET_OS_MAC
-#define DEFAULT_SECURE_PROFILE_PATH "/Library/Preferences/edu.mit.Kerberos:/etc/krb5.conf:@SYSCONFDIR/krb5.conf"
+#define DEFAULT_SECURE_PROFILE_PATH "/Library/Preferences/edu.mit.Kerberos:/etc/krb5.conf@SYSCONFCONF"
 #define DEFAULT_PROFILE_PATH        ("~/Library/Preferences/edu.mit.Kerberos" ":" DEFAULT_SECURE_PROFILE_PATH)
 #define KRB5_PLUGIN_BUNDLE_DIR       "/System/Library/KerberosPlugins/KerberosFrameworkPlugins"
 #define KDB5_PLUGIN_BUNDLE_DIR       "/System/Library/KerberosPlugins/KerberosDatabasePlugins"
 #define KRB5_AUTHDATA_PLUGIN_BUNDLE_DIR  "/System/Library/KerberosPlugins/KerberosAuthDataPlugins"
 #else
-#define DEFAULT_SECURE_PROFILE_PATH     "/etc/krb5.conf:@SYSCONFDIR/krb5.conf"
+#define DEFAULT_SECURE_PROFILE_PATH     "/etc/krb5.conf@SYSCONFCONF"
 #define DEFAULT_PROFILE_PATH        DEFAULT_SECURE_PROFILE_PATH
 #endif
 #endif /* _WINDOWS  */