From 4e58da1aacb709d84ad4160d53ab35c459b33b90 Mon Sep 17 00:00:00 2001
From: Mitchell Foral <unknown>
Date: Wed, 23 Mar 2022 09:01:56 +1100
Subject: On GTK, scroll horizontally with shift + scroll wheel.

---
 doc/ScintillaHistory.html |  3 +++
 gtk/ScintillaGTK.cxx      | 11 ++++-------
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/doc/ScintillaHistory.html b/doc/ScintillaHistory.html
index 544fcd11f..7432aee44 100644
--- a/doc/ScintillaHistory.html
+++ b/doc/ScintillaHistory.html
@@ -585,6 +585,9 @@
 	<a href="https://sourceforge.net/p/scintilla/feature-requests/1431/">Feature #1431</a>.
 	</li>
 	<li>
+	On GTK, scroll horizontally with shift + scroll wheel.
+	</li>
+	<li>
 	Fix crash with unexpected right-to-left text on GTK.
 	<a href="https://sourceforge.net/p/scintilla/bugs/2309/">Bug #2309</a>.
 	</li>
diff --git a/gtk/ScintillaGTK.cxx b/gtk/ScintillaGTK.cxx
index dd22dcbc9..a1ac3adf8 100755
--- a/gtk/ScintillaGTK.cxx
+++ b/gtk/ScintillaGTK.cxx
@@ -1999,11 +1999,6 @@ gint ScintillaGTK::ScrollEvent(GtkWidget *widget, GdkEventScroll *event) {
 		// issues spurious button 2 mouse events during wheeling, which can cause
 		// problems (a patch for both was submitted by archaeopteryx.com on 13Jun2001)
 
-		// Data zoom not supported
-		if (event->state & GDK_SHIFT_MASK) {
-			return FALSE;
-		}
-
 #if GTK_CHECK_VERSION(3,4,0)
 		// Smooth scrolling not supported
 		if (event->direction == GDK_SCROLL_SMOOTH) {
@@ -2012,8 +2007,10 @@ gint ScintillaGTK::ScrollEvent(GtkWidget *widget, GdkEventScroll *event) {
 #endif
 
 		// Horizontal scrolling
-		if (event->direction == GDK_SCROLL_LEFT || event->direction == GDK_SCROLL_RIGHT) {
-			sciThis->HorizontalScrollTo(sciThis->xOffset + cLineScroll);
+		if (event->direction == GDK_SCROLL_LEFT || event->direction == GDK_SCROLL_RIGHT || event->state & GDK_SHIFT_MASK) {
+			int hScroll = gtk_adjustment_get_step_increment(sciThis->adjustmenth);
+			hScroll *= cLineScroll; // scroll by this many characters
+			sciThis->HorizontalScrollTo(sciThis->xOffset + hScroll);
 
 			// Text font size zoom
 		} else if (event->state & GDK_CONTROL_MASK) {
-- 
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