Index: library/scrlbar.tcl
==================================================================
--- library/scrlbar.tcl
+++ library/scrlbar.tcl
@@ -129,20 +129,14 @@
 }
 }
 
 if {[tk windowingsystem] eq "aqua"} {
     bind Scrollbar <MouseWheel> {
-	tk::ScrollByUnits %W v [expr {-(%D)}]
+	tk::ScrollByUnits %W hv [expr {-(%D)}]
     }
     bind Scrollbar <Option-MouseWheel> {
-	tk::ScrollByUnits %W v [expr {-10 * (%D)}]
-    }
-    bind Scrollbar <Shift-MouseWheel> {
-	tk::ScrollByUnits %W h [expr {-(%D)}]
-    }
-    bind Scrollbar <Shift-Option-MouseWheel> {
-	tk::ScrollByUnits %W h [expr {-10 * (%D)}]
+	tk::ScrollByUnits %W hv [expr {-10 * (%D)}]
     }
 } else {
     # We must make sure that positive and negative movements are rounded
     # equally to integers, avoiding the problem that
     #     (int)1/30 = 0,
@@ -149,31 +143,22 @@
     # but
     #     (int)-1/30 = -1
     # The following code ensure equal +/- behaviour.
     bind Scrollbar <MouseWheel> {
 	if {%D >= 0} {
-	    tk::ScrollByUnits %W v [expr {-%D/30}]
-	} else {
-	    tk::ScrollByUnits %W v [expr {(29-%D)/30}]
-	}
-    }
-    bind Scrollbar <Shift-MouseWheel> {
-	if {%D >= 0} {
-	    tk::ScrollByUnits %W h [expr {-%D/30}]
-	} else {
-	    tk::ScrollByUnits %W h [expr {(29-%D)/30}]
+	    tk::ScrollByUnits %W hv [expr {-%D/30}]
+	} else {
+	    tk::ScrollByUnits %W hv [expr {(29-%D)/30}]
 	}
     }
 }
 
 if {[tk windowingsystem] eq "x11"} {
-    bind Scrollbar <Button-4> {tk::ScrollByUnits %W v -5}
-    bind Scrollbar <Button-5> {tk::ScrollByUnits %W v 5}
-    bind Scrollbar <Shift-Button-4> {tk::ScrollByUnits %W h -5}
-    bind Scrollbar <Shift-Button-5> {tk::ScrollByUnits %W h 5}
-    bind Scrollbar <Button-6> {tk::ScrollByUnits %W h -5}
-    bind Scrollbar <Button-7> {tk::ScrollByUnits %W h 5}
+    bind Scrollbar <Button-4> {tk::ScrollByUnits %W hv -5}
+    bind Scrollbar <Button-5> {tk::ScrollByUnits %W hv 5}
+    bind Scrollbar <Button-6> {tk::ScrollByUnits %W hv -5}
+    bind Scrollbar <Button-7> {tk::ScrollByUnits %W hv 5}
 }
 
 # tk::ScrollButtonDown --
 # This procedure is invoked when a button is pressed in a scrollbar.
 # It changes the way the scrollbar is displayed and takes actions

Index: library/ttk/scrollbar.tcl
==================================================================
--- library/ttk/scrollbar.tcl
+++ library/ttk/scrollbar.tcl
@@ -19,18 +19,17 @@
 
 # Redirect scrollwheel bindings to the scrollbar widget
 #
 # The shift-bindings scroll left/right (not up/down)
 # if a widget has both possibilities
-set eventList [list <MouseWheel> <Shift-MouseWheel>]
+set eventList [list <MouseWheel>]
 switch [tk windowingsystem] {
     aqua {
-        lappend eventList <Option-MouseWheel> <Shift-Option-MouseWheel>
+        lappend eventList <Option-MouseWheel>
     }
     x11 {
-        lappend eventList <Button-4> <Button-5> <Button-6> <Button-7>\
-                <Shift-Button-4> <Shift-Button-5>
+        lappend eventList <Button-4> <Button-5> <Button-6> <Button-7>
     }
 }
 foreach event $eventList {
     bind TScrollbar $event [bind Scrollbar $event]
 }

Index: tests/scrollbar.test
==================================================================
--- tests/scrollbar.test
+++ tests/scrollbar.test
@@ -712,11 +712,11 @@
     .t index @0,0
 } -cleanup {
     destroy .t .s
 } -result {5.0}
 
-test scrollbar-10.2.1 {<MouseWheel> event on scrollbar} -constraints {notAqua} -setup {
+test scrollbar-10.2.1 {<Shift-MouseWheel> event on horizontal scrollbar} -constraints {notAqua} -setup {
     destroy .t .s
 } -body {
     pack [text .t -xscrollcommand {.s set} -wrap none] -side top
     for {set i 1} {$i < 100} {incr i} {.t insert end "Char $i "}
     pack [scrollbar .s -command {.t xview} -orient horizontal] -fill x -expand 1 -side top
@@ -726,11 +726,11 @@
     after 200 {set eventprocessed 1} ; vwait eventprocessed
     .t index @0,0
 } -cleanup {
     destroy .t .s
 } -result {1.4}
-test scrollbar-10.2.2 {<MouseWheel> event on scrollbar} -constraints {aqua} -setup {
+test scrollbar-10.2.2 {<Shift-MouseWheel> event on horizontal scrollbar} -constraints {aqua} -setup {
     destroy .t .s
 } -body {
     pack [text .t -xscrollcommand {.s set} -wrap none] -side top
     for {set i 1} {$i < 100} {incr i} {.t insert end "Char $i "}
     pack [scrollbar .s -command {.t xview} -orient horizontal] -fill x -expand 1 -side top
@@ -737,10 +737,38 @@
     update
     focus -force .s
     event generate .s <Shift-MouseWheel> -delta -4
     after 200 {set eventprocessed 1} ; vwait eventprocessed
     .t index @0,0
+} -cleanup {
+    destroy .t .s
+} -result {1.4}
+test scrollbar-10.2.3 {<MouseWheel> event on horizontal scrollbar} -constraints {notAqua} -setup {
+    destroy .t .s
+} -body {
+    pack [text .t -xscrollcommand {.s set} -wrap none] -side top
+    for {set i 1} {$i < 100} {incr i} {.t insert end "Char $i "}
+    pack [scrollbar .s -command {.t xview} -orient horizontal] -fill x -expand 1 -side top
+    update
+    focus -force .s
+    event generate .s <MouseWheel> -delta -120
+    after 200 {set eventprocessed 1} ; vwait eventprocessed
+    .t index @0,0
+} -cleanup {
+    destroy .t .s
+} -result {1.4}
+test scrollbar-10.2.4 {<MouseWheel> event on horizontal scrollbar} -constraints {aqua} -setup {
+    destroy .t .s
+} -body {
+    pack [text .t -xscrollcommand {.s set} -wrap none] -side top
+    for {set i 1} {$i < 100} {incr i} {.t insert end "Char $i "}
+    pack [scrollbar .s -command {.t xview} -orient horizontal] -fill x -expand 1 -side top
+    update
+    focus -force .s
+    event generate .s <MouseWheel> -delta -4
+    after 200 {set eventprocessed 1} ; vwait eventprocessed
+    .t index @0,0
 } -cleanup {
     destroy .t .s
 } -result {1.4}
 
 test scrollbar-11.1 {bug fix: [011706ec42] Scrollbar unsafe wrt widget destruction} -body {

Index: tests/ttk/scrollbar.test
==================================================================
--- tests/ttk/scrollbar.test
+++ tests/ttk/scrollbar.test
@@ -67,10 +67,96 @@
     wm geometry . 200x200
     update
     set w [winfo width .tsb] ; set h [winfo height .tsb]
     expr {$h < $w}
 } -result 1
+
+test scrollbar-10.1.1 {<MouseWheel> event on scrollbar} -constraints {notAqua} -setup {
+    destroy .t .s
+} -body {
+    pack [text .t -yscrollcommand {.s set}] -side left
+    for {set i 1} {$i < 100} {incr i} {.t insert end "Line $i\n"}
+    pack [ttk::scrollbar .s -command {.t yview}] -fill y -expand 1 -side left
+    update
+    focus -force .s
+    event generate .s <MouseWheel> -delta -120
+    after 200 {set eventprocessed 1} ; vwait eventprocessed
+    .t index @0,0
+} -cleanup {
+    destroy .t .s
+} -result {5.0}
+test scrollbar-10.1.2 {<MouseWheel> event on scrollbar} -constraints {aqua} -setup {
+    destroy .t .s
+} -body {
+    pack [text .t -yscrollcommand {.s set}] -side left
+    for {set i 1} {$i < 100} {incr i} {.t insert end "Line $i\n"}
+    pack [ttk::scrollbar .s -command {.t yview}] -fill y -expand 1 -side left
+    update
+    focus -force .s
+    event generate .s <MouseWheel> -delta -4
+    after 200 {set eventprocessed 1} ; vwait eventprocessed
+    .t index @0,0
+} -cleanup {
+    destroy .t .s
+} -result {5.0}
+
+test scrollbar-10.2.1 {<Shift-MouseWheel> event on horizontal scrollbar} -constraints {notAqua} -setup {
+    destroy .t .s
+} -body {
+    pack [text .t -xscrollcommand {.s set} -wrap none] -side top
+    for {set i 1} {$i < 100} {incr i} {.t insert end "Char $i "}
+    pack [ttk::scrollbar .s -command {.t xview} -orient horizontal] -fill x -expand 1 -side top
+    update
+    focus -force .s
+    event generate .s <Shift-MouseWheel> -delta -120
+    after 200 {set eventprocessed 1} ; vwait eventprocessed
+    .t index @0,0
+} -cleanup {
+    destroy .t .s
+} -result {1.4}
+test scrollbar-10.2.2 {<Shift-MouseWheel> event on horizontal scrollbar} -constraints {aqua} -setup {
+    destroy .t .s
+} -body {
+    pack [text .t -xscrollcommand {.s set} -wrap none] -side top
+    for {set i 1} {$i < 100} {incr i} {.t insert end "Char $i "}
+    pack [ttk::scrollbar .s -command {.t xview} -orient horizontal] -fill x -expand 1 -side top
+    update
+    focus -force .s
+    event generate .s <Shift-MouseWheel> -delta -4
+    after 200 {set eventprocessed 1} ; vwait eventprocessed
+    .t index @0,0
+} -cleanup {
+    destroy .t .s
+} -result {1.4}
+test scrollbar-10.2.3 {<MouseWheel> event on horizontal scrollbar} -constraints {notAqua} -setup {
+    destroy .t .s
+} -body {
+    pack [text .t -xscrollcommand {.s set} -wrap none] -side top
+    for {set i 1} {$i < 100} {incr i} {.t insert end "Char $i "}
+    pack [ttk::scrollbar .s -command {.t xview} -orient horizontal] -fill x -expand 1 -side top
+    update
+    focus -force .s
+    event generate .s <MouseWheel> -delta -120
+    after 200 {set eventprocessed 1} ; vwait eventprocessed
+    .t index @0,0
+} -cleanup {
+    destroy .t .s
+} -result {1.4}
+test scrollbar-10.2.4 {<MouseWheel> event on horizontal scrollbar} -constraints {aqua} -setup {
+    destroy .t .s
+} -body {
+    pack [text .t -xscrollcommand {.s set} -wrap none] -side top
+    for {set i 1} {$i < 100} {incr i} {.t insert end "Char $i "}
+    pack [ttk::scrollbar .s -command {.t xview} -orient horizontal] -fill x -expand 1 -side top
+    update
+    focus -force .s
+    event generate .s <MouseWheel> -delta -4
+    after 200 {set eventprocessed 1} ; vwait eventprocessed
+    .t index @0,0
+} -cleanup {
+    destroy .t .s
+} -result {1.4}
 
 #
 # Scale tests:
 #