From e3d621c66dd61797366c632e21d9edb80d9c669b Mon Sep 17 00:00:00 2001
From: Olof hagsand <olof@hagsand.se>
Date: Tue, 1 Nov 2022 11:13:40 +0100
Subject: [PATCH] Fixed: SEGV when using NETCONF get filter xpath and
 non-existent key   * eg `select="/ex:table[ex:non-exist='a']`

---
 CHANGELOG.md                   |  2 ++
 lib/src/clixon_xpath_eval.c    | 16 ++++++++++++----
 test/test_autocli_extension.sh |  4 ++++
 3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1e634fcc..6d4d49b6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -83,6 +83,8 @@ Developers may need to change their code
 
 ### Corrected Bugs
 
+* Fixed: SEGV when using NETCONF get filter xpath and non-existent key
+  * eg `select="/ex:table[ex:non-exist='a']`
 * Fixed: [CLI Show config JSON with multiple top-level elements is broken](https://github.com/clicon/clixon/issues/381)
 * Fixed: [Non-obvious behavior of clixon_snmp after snmpset command when transaction validation returns an error](https://github.com/clicon/clixon/issues/375)
   * Fixed by validating writes on ACTION instead of COMMIT since libnetsnmp seems not to accept commit errors
diff --git a/lib/src/clixon_xpath_eval.c b/lib/src/clixon_xpath_eval.c
index 6a5f4a2f..22067666 100644
--- a/lib/src/clixon_xpath_eval.c
+++ b/lib/src/clixon_xpath_eval.c
@@ -845,10 +845,18 @@ xp_relop(xp_ctx    *xc1,
                 case XO_EQ:
                     if (s1 == NULL && s2 == NULL)
                         xr->xc_bool = 1;
-                    else if (s1 == NULL && strlen(s2) == 0)
-                        xr->xc_bool = 1;
-                    else if (strlen(s1) == 0 && s2 == NULL)
-                        xr->xc_bool = 1;
+                    if (s1 == NULL){
+                        if (strlen(s2) == 0)
+                            xr->xc_bool = 1;
+                        else
+                            xr->xc_bool = 0;
+                    }
+                    else if (s2 == NULL){
+                        if (strlen(s1) == 0)
+                            xr->xc_bool = 1;
+                        else
+                            xr->xc_bool = 0;
+                    }
                     else
                         xr->xc_bool = (strcmp(s1, s2)==0);
                     break;
diff --git a/test/test_autocli_extension.sh b/test/test_autocli_extension.sh
index c92b9ded..805636f5 100755
--- a/test/test_autocli_extension.sh
+++ b/test/test_autocli_extension.sh
@@ -133,6 +133,10 @@ EOF
     new "check datastore using netconf"
     expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><get-config><source><candidate/></source><filter type=\"xpath\" select=\"/ex:table/ex:parameter[ex:name='x']\" xmlns:ex=\"urn:example:clixon\" /></get-config></rpc>" "" "<rpc-reply $DEFAULTNS><data>$XML</data></rpc-reply>"
 
+    # Test not right context but could not find other test where it fits
+    new "negative test"
+    expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><get-config><source><candidate/></source><filter type=\"xpath\" select=\"/ex:table[ex:parameter='x']\" xmlns:ex=\"urn:example:clixon\" /></get-config></rpc>" "" "<rpc-reply $DEFAULTNS><data/></rpc-reply>"
+
     new "check datastore direct access"
     expectpart "$($clixon_util_datastore -d candidate -b $dir -y $fyang -Y ${YANG_INSTALLDIR} -Y $dir get /)" 0 "$XML"