Fixed: [if choice is declared with multiple elements or leaf-list with in a case scope , addition or updation is not happening as expected](https://github.com/clicon/clixon/issues/327)

* This includes several choice/case adjustments to follow RFC 7950 Sec 7.9 better

CHANGELOG.md

@@ -111,6 +111,8 @@ Users may have to change how they access the system
 
 ### Corrected Bugs
 
+* Fixed: [if choice is declared with multiple elements or leaf-list with in a case scope , addition or updation is not happening as expected](https://github.com/clicon/clixon/issues/327)
+  * This includes several choice/case adjustments to follow RFC 7950 Sec 7.9 better
 * Fixed: HTTP/1 parse error for '/' path
 * Fixed: YANG if-feature in config file of disables feature did not work, was always on
   * This does not apply to the datastore, only the config file itself.

lib/src/clixon_datastore_write.c

@@ -274,6 +274,86 @@ check_when_condition(cxobj              *x0p,
     goto done;
 }
 
+/*! Check if choice nodes and implicitly remove all other cases.
+ *
+ * Special case is if yc parent (yp) is choice/case
+ * then find x0 child with same yc even though it does not match lexically
+ * However this will give another y0c != yc
+ * @param[in]  x0      Base tree node
+ * @param[in]  y1c     Yang spec of tree child. If null revert to linear search.
+ * @retval     0       OK
+ * @retval    -1       Error
+ *
+ * From RFC 7950 Sec 7.9
+ * Since only one of the choice's cases can be valid at any time in the
+ * data tree, the creation of a node from one case implicitly deletes
+ * all nodes from all other cases.  If a request creates a node from a
+ * case, the server will delete any existing nodes that are defined in
+ * other cases inside the choice.
+ */
+static int
+check_delete_existing_case(cxobj     *x0,
+    			   yang_stmt *y1c)
+{
+    int        retval = -1;
+    yang_stmt *yp;
+    yang_stmt *y0case;
+    yang_stmt *y1case;
+    yang_stmt *y0choice;
+    yang_stmt *y1choice;
+    yang_stmt *y0c;
+    cxobj     *x0c;
+    cxobj     *x0prev;
+
+    if ((yp = yang_parent_get(y1c)) == NULL)
+	goto ok;
+    if (yang_keyword_get(yp) == Y_CASE){
+	y1case = yp;
+	y1choice = yang_parent_get(y1case);
+    }
+    else if (yang_keyword_get(yp) == Y_CHOICE){
+	y1case = NULL;
+	y1choice = yp;
+    }
+    else
+	goto ok;
+    x0prev = NULL;
+    x0c = NULL;
+    while ((x0c = xml_child_each(x0, x0c, CX_ELMNT)) != NULL) {
+	if ((y0c = xml_spec(x0c)) == NULL ||
+	    (yp = yang_parent_get(y0c)) == NULL){
+	    x0prev = x0c;
+	    continue;
+	}
+	if (yang_keyword_get(yp) == Y_CASE){
+	    y0case = yp;
+	    y0choice = yang_parent_get(y0case);
+	}
+	else if (yang_keyword_get(yp) == Y_CHOICE){
+	    y0case = NULL;
+	    y0choice = yp;
+	}
+	else{
+	    x0prev = x0c;
+	    continue;
+	}
+	if (y0choice == y1choice){
+	    if (y0case == NULL ||
+		y0case != y1case){
+		if (xml_purge(x0c) < 0)
+		    goto done;
+		x0c = x0prev;
+		continue;
+	    }
+	}
+	x0prev = x0c;
+    }
+ ok:
+    retval = 0;
+ done:
+    return retval;
+}
+
 /*! Modify a base tree x0 with x1 with yang spec y according to operation op
  * @param[in]  h        Clicon handle
  * @param[in]  x0       Base xml tree (can be NULL in add scenarios)
@@ -724,16 +804,13 @@ text_modify(clicon_handle       h,
 			       x1cname, yang_find_mynamespace(y0));
 		    goto done;
 		}
+		/* Check if existing case should be deleted */
+		if (check_delete_existing_case(x0, yc) < 0)
+		    goto done;
 		/* See if there is a corresponding node in the base tree */
 		x0c = NULL;
 		if (match_base_child(x0, x1c, yc, &x0c) < 0)
 		    goto done;
-		if (x0c && (yc != xml_spec(x0c))){
-		    /* There is a match but is should be replaced (choice)*/
-		    if (xml_purge(x0c) < 0)
-			goto done;
-		    x0c = NULL;
-		}
 		x0vec[i++] = x0c; /* != NULL if x0c is matching x1c */
 	    }
 	    /* Second pass: Loop through children of the x1 modification tree again

lib/src/clixon_validate.c

@@ -1128,7 +1128,7 @@ check_list_unique_minmax(cxobj  *xt,
 	    ych = y;
 	keyw = yang_keyword_get(y);
 	if (keyw != Y_LIST && keyw != Y_LEAF_LIST){
-	    if (yprev != NULL && y == yprev && yang_choice(y)==NULL){
+	    if (yprev != NULL && y == yprev){
 		/* Only lists and leaf-lists are allowed to be many 
 		 * This checks duplicate container and leafs
 		 */

lib/src/clixon_xml_sort.c

@@ -1148,10 +1148,6 @@ match_base_child(cxobj      *x0,
     cg_var      *cvi;
     cxobj       *xb;
     char        *keyname;
-    cxobj       *x0c = NULL;
-    yang_stmt   *y0c;
-    yang_stmt   *y0p;
-    yang_stmt   *yp; /* yang parent */
     clixon_xvec *xvec = NULL;
     
     *x0cp = NULL; /* init return value */
@@ -1160,21 +1156,6 @@ match_base_child(cxobj      *x0,
 	*x0cp = xml_find(x0, xml_name(x1c));
 	goto ok;
     }
-    /* Special case is if yc parent (yp) is choice/case
-     * then find x0 child with same yc even though it does not match lexically
-     * However this will give another y0c != yc
-     */
-    if ((yp = yang_choice(yc)) != NULL){
-	x0c = NULL;
-	while ((x0c = xml_child_each(x0, x0c, CX_ELMNT)) != NULL) {
-	    if ((y0c = xml_spec(x0c)) != NULL &&
-		(y0p = yang_choice(y0c)) != NULL &&
-		y0p == yp)
-		break;	/* x0c will have a value */
-	}
-	*x0cp = x0c;
-	goto ok; /* What to do if not found? */
-    }
     switch (yang_keyword_get(yc)){
     case Y_CONTAINER: 	/* Equal regardless */
     case Y_LEAF: 	/* Equal regardless */

test/test_choice.sh

@@ -148,7 +148,7 @@ if [ $BE -ne 0 ]; then
     start_backend -s init -f $cfg
 fi
 
-new "waiting"
+new "wait backend"
 wait_backend
 
 if [ $RC -ne 0 ]; then
@@ -158,10 +158,11 @@ if [ $RC -ne 0 ]; then
     new "start restconf daemon"
     start_restconf -f $cfg
 
-    new "waiting"
-    wait_restconf
 fi
 
+new "wait restconf"
+wait_restconf
+
 # First vanilla (protocol) case
 new "netconf validate empty"
 expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><validate><source><candidate/></source></validate></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
@@ -283,26 +284,32 @@ expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS>
 # Choice with multiple items
 
 new "netconf choice multiple items first"
-expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><system xmlns=\"urn:example:config\" op=\"replace\">
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><system xmlns=\"urn:example:config\" nc:operation=\"replace\" xmlns:nc=\"$BASENS\">
   <ma>0</ma>
   <ma>1</ma>
   <mb>2</mb>
 </system></config></edit-config></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
 
+new "netconf get multiple items"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><get-config><source><candidate/></source></get-config></rpc>" "<rpc-reply $DEFAULTNS><data><system xmlns=\"urn:example:config\"><ma>0</ma><ma>1</ma><mb>2</mb></system>" ""
+
 new "netconf validate multiple ok"
 expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><validate><source><candidate/></source></validate></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
 
 new "netconf choice multiple items second"
-expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><system xmlns=\"urn:example:config\" op=\"replace\">
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><system xmlns=\"urn:example:config\" nc:operation=\"replace\" xmlns:nc=\"$BASENS\">
   <mb>0</mb>
   <mb>1</mb>
 </system></config></edit-config></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
 
-new "netconf validate multiple ok"
+new "netconf get items second"
-expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><validate><source><candidate/></source></validate></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><get-config><source><candidate/></source></get-config></rpc>" "<rpc-reply $DEFAULTNS><data><system xmlns=\"urn:example:config\"><mb>0</mb><mb>1</mb></system>" ""
+
+new "netconf validate items second expect fail"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><validate><source><candidate/></source></validate></rpc>" "" "<rpc-reply $DEFAULTNS><rpc-error><error-type>protocol</error-type><error-tag>operation-failed</error-tag><error-app-tag>too-many-elements</error-app-tag><error-severity>error</error-severity><error-path>/system/mb</error-path></rpc-error></rpc-reply>"
 
 new "netconf choice multiple items mix"
-expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><system xmlns=\"urn:example:config\" op=\"replace\">
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><system xmlns=\"urn:example:config\" nc:operation=\"replace\" xmlns:nc=\"$BASENS\">
   <ma>0</ma>
   <mb>2</mb>
   <mc>2</mc>
@@ -311,6 +318,23 @@ expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS>
 new "netconf validate multiple error"
 expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><validate><source><candidate/></source></validate></rpc>" "" "<rpc-reply $DEFAULTNS><rpc-error><error-type>application</error-type><error-tag>bad-element</error-tag><error-info><bad-element>mc</bad-element></error-info><error-severity>error</error-severity><error-message>Element in choice statement already exists</error-message></rpc-error></rpc-reply>"
 
+# Double merge
+new "netconf choice single item"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><system xmlns=\"urn:example:config\" nc:operation=\"replace\" xmlns:nc=\"$BASENS\">
+  <ma>12</ma>
+</system></config></edit-config></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
+
+new "netconf choice merge second item"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><system xmlns=\"urn:example:config\" nc:operation=\"merge\" xmlns:nc=\"$BASENS\">
+  <mb>99</mb>
+</system></config></edit-config></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
+
+new "netconf get both items"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><get-config><source><candidate/></source></get-config></rpc>" "<rpc-reply $DEFAULTNS><data><system xmlns=\"urn:example:config\"><ma>12</ma><mb>99</mb></system>" ""
+
+new "netconf validate ok"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><validate><source><candidate/></source></validate></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
+
 if [ $RC -ne 0 ]; then
     new "Kill restconf daemon"
     stop_restconf