Index: generic/ttk/ttkTreeview.c
==================================================================
--- generic/ttk/ttkTreeview.c
+++ generic/ttk/ttkTreeview.c
@@ -2677,11 +2677,11 @@
 static int TreeviewDeleteCommand(
     void *recordPtr, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[])
 {
     Treeview *tv = recordPtr;
     TreeItem **items, *delq;
-    int i, selItemDeleted = 0;
+    int i, selChange = 0;
 
     if (objc != 3) {
 	Tcl_WrongNumArgs(interp, 2, objv, "items");
 	return TCL_ERROR;
     }
@@ -2705,11 +2705,11 @@
     /* Remove items from hash table.
      */
     delq = 0;
     for (i=0; items[i]; ++i) {
         if (items[i]->state & TTK_STATE_SELECTED) {
-            selItemDeleted = 1;
+            selChange = 1;
         }
 	delq = DeleteItems(items[i], delq);
     }
 
     /* Free items:
@@ -2723,11 +2723,11 @@
 	FreeItem(delq);
 	delq = next;
     }
 
     ckfree(items);
-    if (selItemDeleted) {
+    if (selChange) {
         TtkSendVirtualEvent(tv->core.tkwin, "TreeviewSelect");
     }
     TtkRedisplayWidget(&tv->core);
     return TCL_OK;
 }
@@ -2952,11 +2952,11 @@
     static const char *selopStrings[] = {
 	"set", "add", "remove", "toggle", NULL
     };
 
     Treeview *tv = recordPtr;
-    int selop, i;
+    int selop, i, selChange = 0;
     TreeItem *item, **items;
 
     if (objc == 2) {
 	Tcl_Obj *result = Tcl_NewListObj(0,0);
 	for (item = tv->tree.root->children; item; item=NextPreorder(item)) {
@@ -2983,33 +2983,64 @@
     }
 
     switch (selop)
     {
 	case SELECTION_SET:
+	    for (item=tv->tree.root; item; item=NextPreorder(item)) {
+		int inSetList = 0;
+
+		for (i=0; items[i]; ++i) {
+		    if (item == items[i]) {
+			inSetList = 1;
+			if (!(item->state & TTK_STATE_SELECTED)) {
+			    /* Item newly selected */
+			    selChange = 1;
+			}
+			break;
+		    }
+		}
+		if (!inSetList && (item->state & TTK_STATE_SELECTED)) {
+		    /* Item newly deselected */
+		    selChange = 1;
+		}
+		if (selChange) break;
+	    }
 	    for (item=tv->tree.root; item; item=NextPreorder(item)) {
 		item->state &= ~TTK_STATE_SELECTED;
 	    }
-	    /*FALLTHRU*/
-	case SELECTION_ADD:
 	    for (i=0; items[i]; ++i) {
 		items[i]->state |= TTK_STATE_SELECTED;
+	    }
+	    break;
+	case SELECTION_ADD:
+	    for (i=0; items[i]; ++i) {
+		if (!(items[i]->state & TTK_STATE_SELECTED)) {
+		    items[i]->state |= TTK_STATE_SELECTED;
+		    selChange = 1;
+		}
 	    }
 	    break;
 	case SELECTION_REMOVE:
 	    for (i=0; items[i]; ++i) {
-		items[i]->state &= ~TTK_STATE_SELECTED;
+		if (items[i]->state & TTK_STATE_SELECTED) {
+		    items[i]->state &= ~TTK_STATE_SELECTED;
+		    selChange = 1;
+		}
 	    }
 	    break;
 	case SELECTION_TOGGLE:
 	    for (i=0; items[i]; ++i) {
 		items[i]->state ^= TTK_STATE_SELECTED;
+		selChange = 1;
 	    }
 	    break;
     }
 
     ckfree(items);
-    TtkSendVirtualEvent(tv->core.tkwin, "TreeviewSelect");
+    if (selChange) {
+	TtkSendVirtualEvent(tv->core.tkwin, "TreeviewSelect");
+    }
     TtkRedisplayWidget(&tv->core);
 
     return TCL_OK;
 }
 

Index: tests/ttk/treeview.test
==================================================================
--- tests/ttk/treeview.test
+++ tests/ttk/treeview.test
@@ -458,34 +458,113 @@
 
 test treeview-8.5 "Selection - bad operation" -body {
     .tv selection badop foo
 } -returnCodes error -match glob -result {bad selection operation "badop": must be *}
 
-test treeview-8.6 "Selection - <<TreeviewSelect>> on selection add" -body {
-    .tv selection set {}
-    bind .tv <<TreeviewSelect>> {set res 1}
-    set res 0
-    .tv selection add newnode.n1
-    update
-    set res
-} -result {1}
-
-test treeview-8.7 "<<TreeviewSelect>> on selected item deletion" -body {
-    .tv selection set {}
-    .tv insert "" end -id selectedDoomed -text DeadItem
-    .tv insert "" end -id doomed -text AlsoDead
-    .tv selection add selectedDoomed
-    update
-    bind .tv <<TreeviewSelect>> {lappend res 1}
-    set res 0
-    .tv delete doomed
-    update
-    set res [expr {$res == 0}]
-    .tv delete selectedDoomed
-    update
-    set res
-} -result {1 1}
+test treeview-8.7 "<<TreeviewSelect>> when deleting items" -body {
+    .tv delete [.tv children {}]
+    .tv insert "" end -id myItem1 -text FirstItem
+    .tv insert "" end -id myItem2 -text SecondItem
+    .tv selection add myItem1
+    update
+    bind .tv <<TreeviewSelect>> {lappend res $val}
+    set res {}
+    set val 1
+    .tv delete myItem2  ; # no <<TreeviewSelect>> (selection unchanged)
+    update
+    set val 2
+    .tv delete myItem1  ; # <<TreeviewSelect>> triggers
+    update
+    set res
+} -result {2}
+
+test treeview-8.8 "<<TreeviewSelect>> when setting the selection" -body {
+    .tv delete [.tv children {}]
+    .tv insert "" end -id myItem1 -text FirstItem
+    .tv insert "" end -id myItem2 -text SecondItem
+    update
+    bind .tv <<TreeviewSelect>> {lappend res $val}
+    set res {}
+    set val 1
+    .tv selection set ""       ; # no <<TreeviewSelect>> (selection unchanged)
+    update
+    set val 2
+    .tv selection set myItem1  ; # <<TreeviewSelect>> triggers
+    update
+    set val 3
+    .tv selection set myItem1  ; # no <<TreeviewSelect>> (already selected)
+    update
+    set val 4
+    .tv selection set {myItem1 myItem2}  ; # <<TreeviewSelect>> triggers
+    update
+    set val 5
+    .tv selection set {myItem2}  ; # <<TreeviewSelect>> triggers
+    update
+    set res
+} -result {2 4 5}
+
+test treeview-8.9 "<<TreeviewSelect>> when removing items from the selection" -body {
+    .tv delete [.tv children {}]
+    .tv insert "" end -id myItem1 -text FirstItem
+    .tv selection set myItem1
+    update
+    bind .tv <<TreeviewSelect>> {lappend res $val}
+    set res {}
+    set val 1
+    .tv selection remove ""       ; # no <<TreeviewSelect>> (selection unchanged)
+    update
+    set val 2
+    .tv selection remove myItem1  ; # <<TreeviewSelect>> triggers
+    update
+    set val 3
+    .tv selection remove myItem1  ; # no <<TreeviewSelect>> (selection unchanged)
+    update
+    set res
+} -result {2}
+
+test treeview-8.10 "<<TreeviewSelect>> when adding items in the selection" -body {
+    .tv delete [.tv children {}]
+    .tv insert "" end -id myItem1 -text FirstItem
+    .tv insert "" end -id myItem2 -text SecondItem
+    .tv insert "" end -id myItem3 -text ThirdItem
+    update
+    bind .tv <<TreeviewSelect>> {lappend res $val}
+    set res {}
+    set val 1
+    .tv selection add myItem2  ; # <<TreeviewSelect>> triggers
+    update
+    set val 2
+    .tv selection add myItem2  ; # no <<TreeviewSelect>> (selection unchanged)
+    update
+    set val 3
+    .tv selection add myItem3  ; # <<TreeviewSelect>> triggers
+    update
+    set res
+} -result {1 3}
+
+test treeview-8.11 "<<TreeviewSelect>> when toggling" -body {
+    .tv delete [.tv children {}]
+    .tv insert "" end -id myItem1 -text FirstItem
+    .tv insert "" end -id myItem2 -text SecondItem
+    .tv insert "" end -id myItem3 -text ThirdItem
+    update
+    bind .tv <<TreeviewSelect>> {lappend res $val}
+    set res {}
+    set val 1
+    .tv selection toggle ""  ; # no <<TreeviewSelect>> (selection unchanged)
+    update
+    set val 2
+    .tv selection toggle {myItem1 myItem3}  ; # <<TreeviewSelect>> triggers
+    update
+    set val 3
+    .tv selection toggle {myItem3 myItem2}  ; # <<TreeviewSelect>> triggers
+    update
+    set val 4
+    .tv selection toggle {myItem3 myItem2}  ; # <<TreeviewSelect>> triggers
+    update
+    set res
+} -result {2 3 4}
 
 ### NEED: more tests for see/yview/scrolling
 
 proc scrollcallback {args} {
     set ::scrolldata $args