Fix issue with <<TreeviewSelect>> event as described in [2a6c62afd9] in the comment dated 2022-05-07. This commit is for 8.6 and was backported from pspjuth's patch [040f5aa0].

4 files changed, 21 insertions, 20 deletions

diff --git a/doc/text.n b/doc/text.n
index c41c6ac..e4bc64d 100644
--- a/doc/text.n
+++ b/doc/text.n
@@ -847,6 +847,9 @@ characters in the text.
 .IP [4]
 Whenever the \fBsel\fR tag range changes a virtual event \fB<<Selection>>\fR
 is generated.
+It might also be generated when selection is affected but not actually changed.
+Further, multiple selection changes could happen before events can be processed
+leading to multiple events with the same visible selection.
 .PP
 The \fBsel\fR tag is automatically defined when a text widget is created, and
 it may not be deleted with the
diff --git a/doc/ttk_treeview.n b/doc/ttk_treeview.n
index 2deb5b5..8494dad 100644
--- a/doc/ttk_treeview.n
+++ b/doc/ttk_treeview.n
@@ -472,6 +472,9 @@ Again, \fBcolumn #0 always refers to the tree column\fR.
 The treeview widget generates the following virtual events.
 .IP <<TreeviewSelect>>
 Generated whenever the selection changes.
+It might also be generated when selection is affected but not actually changed.
+Further, multiple selection changes could happen before events can be processed
+leading to multiple events with the same visible selection.
 .IP <<TreeviewOpen>>
 Generated just before setting the focus item to \fB\-open true\fR.
 .IP <<TreeviewClose>>
diff --git a/generic/ttk/ttkTreeview.c b/generic/ttk/ttkTreeview.c
index 7fd1442..1bb0482 100644
--- a/generic/ttk/ttkTreeview.c
+++ b/generic/ttk/ttkTreeview.c
@@ -2985,30 +2985,16 @@ static int TreeviewSelectionCommand(
     switch (selop)
     {
 	case SELECTION_SET:
+	    /* Clear */
 	    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 */
+		if (item->state & TTK_STATE_SELECTED) {
+		    item->state &= ~TTK_STATE_SELECTED;
 		    selChange = 1;
 		}
-		if (selChange) break;
-	    }
-	    for (item=tv->tree.root; item; item=NextPreorder(item)) {
-		item->state &= ~TTK_STATE_SELECTED;
 	    }
 	    for (i=0; items[i]; ++i) {
 		items[i]->state |= TTK_STATE_SELECTED;
+		selChange = 1;
 	    }
 	    break;
 	case SELECTION_ADD:
diff --git a/tests/ttk/treeview.test b/tests/ttk/treeview.test
index 3ecbddc..6a1964b 100644
--- a/tests/ttk/treeview.test
+++ b/tests/ttk/treeview.test
@@ -490,8 +490,9 @@ test treeview-8.8 "<<TreeviewSelect>> when setting the selection" -body {
     set val 2
     .tv selection set myItem1  ; # <<TreeviewSelect>> triggers
     update
+    # Current implementation generates an event for this case
     set val 3
-    .tv selection set myItem1  ; # no <<TreeviewSelect>> (already selected)
+    .tv selection set myItem1  ; # (already selected)
     update
     set val 4
     .tv selection set {myItem1 myItem2}  ; # <<TreeviewSelect>> triggers
@@ -500,7 +501,9 @@ test treeview-8.8 "<<TreeviewSelect>> when setting the selection" -body {
     .tv selection set {myItem2}  ; # <<TreeviewSelect>> triggers
     update
     set res
-} -result {2 4 5}
+} -cleanup {
+    bind .tv <<TreeviewSelect>> {}
+} -result {2 3 4 5}
 
 test treeview-8.9 "<<TreeviewSelect>> when removing items from the selection" -body {
     .tv delete [.tv children {}]
@@ -519,6 +522,8 @@ test treeview-8.9 "<<TreeviewSelect>> when removing items from the selection" -b
     .tv selection remove myItem1  ; # no <<TreeviewSelect>> (selection unchanged)
     update
     set res
+} -cleanup {
+    bind .tv <<TreeviewSelect>> {}
 } -result {2}
 
 test treeview-8.10 "<<TreeviewSelect>> when adding items in the selection" -body {
@@ -539,6 +544,8 @@ test treeview-8.10 "<<TreeviewSelect>> when adding items in the selection" -body
     .tv selection add myItem3  ; # <<TreeviewSelect>> triggers
     update
     set res
+} -cleanup {
+    bind .tv <<TreeviewSelect>> {}
 } -result {1 3}
 
 test treeview-8.11 "<<TreeviewSelect>> when toggling" -body {
@@ -562,6 +569,8 @@ test treeview-8.11 "<<TreeviewSelect>> when toggling" -body {
     .tv selection toggle {myItem3 myItem2}  ; # <<TreeviewSelect>> triggers
     update
     set res
+} -cleanup {
+    bind .tv <<TreeviewSelect>> {}
 } -result {2 3 4}
 
 ### NEED: more tests for see/yview/scrolling