5 files changed, 36 insertions, 3 deletions

diff --git a/etc/NEWS b/etc/NEWS
index f1da038cb8b..393c352ae42 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -667,6 +667,12 @@ Horizontal scrolling now happens automatically if
 `automatic-hscrolling' is set (the default).  This setting can be
 customized.
 
+If a window is scrolled horizontally with set-window-hscroll, or
+scroll-left/scroll-right (C-x <, C-x >), this serves as a lower bound
+for automatic horizontal scrolling.  Automatic scrolling will scroll
+the text more to the left if necessary, but won't scroll the text more
+to the right than the column set with set-window-hscroll etc.
+
 +++
 ** Tool bar support.
 
diff --git a/etc/TODO b/etc/TODO
index ce15a579bd2..12eb39595f2 100644
--- a/etc/TODO
+++ b/etc/TODO
@@ -143,3 +143,5 @@
 
 * Remove the limitation that window and frame widths and heights can
   be only full columns/lines.
+
+* Add horizontal scroll bars.
diff --git a/lispref/windows.texi b/lispref/windows.texi
index 5d46ed35e9d..95a6c5f7f92 100644
--- a/lispref/windows.texi
+++ b/lispref/windows.texi
@@ -1517,9 +1517,11 @@ left you can scroll, but eventually all the text will disappear off the
 left edge.
 
   In Emacs 21, redisplay automatically alters the horizontal scrolling
-of a window as necessary to ensure that point is always visible.
-However, you can still set the horizontal scrolling value explicitly.
-The value you specify will be used, provided it leaves point visible.
+of a window as necessary to ensure that point is always visible, if
+@code{automatic-hscrolling} is set.  However, you can still set the
+horizontal scrolling value explicitly.  The value you specify serves as
+a lower bound for automatic scrolling, i.e. automatic scrolling
+will not scroll a window to a column less than the specified one.
 
 @deffn Command scroll-left &optional count
 This function scrolls the selected window @var{count} columns to the
diff --git a/man/display.texi b/man/display.texi
index 65d4d2e8e2b..aa3d7de68b7 100644
--- a/man/display.texi
+++ b/man/display.texi
@@ -200,6 +200,12 @@ necessary to keep point visible and not too far from the left or right
 edge.  If you don't want this, customize the variable
 @code{automatic-hscrolling} and set it to nil.
 
+If a window is scrolled horizontally by means of @code{scroll-left}, the
+chosen column serves as a lower bound for automatic horizontal
+scrolling.  Automatic scrolling will continue to scroll the window to
+the left, if necessary, but won't scroll it more to the right than the
+column set by @code{scroll-left}.
+
 @node Follow Mode
 @section Follow Mode
 @cindex Follow mode
diff --git a/src/ChangeLog b/src/ChangeLog
index 83e83509c4d..b9794a8566e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,22 @@
 2000-12-20  Gerd Moellmann  <gerd@gnu.org>
 
+        * xdisp.c (hscroll_window_tree): Take window's min_hscroll
+        into account.
+
+        * window.c (make_window): Initialize window's min_hscroll.
+        (Fset_window_hscroll): Set window's hscroll and min_hscroll.
+        (set_window_buffer, temp_output_buffer_show): Set min_hscroll
+        to zero.
+        (struct saved_window): New member min_hscroll.
+        (SAVED_WINDOW_VECTOR_SIZE): Set to 17.
+        (Fset_window_configuration): Set window's min_hscroll.
+        (save_window_save): Save window's min_hscroll.
+        (compare_window_configurations): Compare min_hscroll values.
+
+        * window.h (struct window): New member min_hscroll.
+
+        * keyboard.c (echo_prompt): Prevent a compiler warning.
+
         * xdisp.c (try_cursor_movement): Fix last change.  The real
         condition is that PT is at the end of the row, and should
         be displayed at the start of the next row.