Merge from origin/emacs-26

49cd561dc6 * test/lisp/tramp-tests.el (tramp-test21-file-links): Spec...
b719f6b20b Loosen strict parsing requirement for desktop files
c7a0c13777 * lisp/xdg.el (xdg-thumb-uri): Fix doc string.
dc6b3560e5 Fix documentation of `make-frame' and related variables an...
3d3778d82a Accept new `always' value for option `buffer-offer-save'
638f64c40a Improve new NS scrolling variable names
d93301242f Document 'replace-buffer-contents' in the manual.
00e4e3e9d2 Fix undecorated frame resizing issues on NS (bug#28512)
820739bbb5 ; * doc/emacs/display.texi (Display Custom): Fix wording.
f2b2201594 ; Spelling and URL fixes
0e143b1fc5 Documentation improvements for 'display-line-numbers'
f656ccdb43 ; Fix typo
d64da52d57 Fix last change in bat-mode.el
908af46abd Fix restoring in GUI sessions desktop saved in TTY sessions
51cbd85454 Improve syntax highlighting in bat-mode
0273916618 Document the 'list-FOO' convention
d24ec58540 Expose viewing conditions in CAM02-UCS metric
a81d5a3d3f Revert "Set frame size to actual requested size (bug#18215)"
0bf066d4b2 Add tests for Edebug
68baca3ee1 Catch more messages in ert-with-message-capture
28e0c410c9 ; * lisp/mouse.el (secondary-selection-exist-p): Doc fix.
31e1d9ef2f Support setting region from secondary selection and vice v...
047f02f00f Fix new copy-directory bug with empty dirs
fbd15836af * doc/lispref/strings.texi (Formatting Strings): Improve i...
f16a8d5dbd Fix 2 testsuite tests for MS-Windows
965cffd89c Rename timer-list to list-timers
a5fec62b51 Provide native touchpad scrolling on macOS
7b3d1c6beb Fix MinGW64 build broken by recent MinGW64 import libraries
c83d0c5fdf Fix crashes in 'move-point-visually' in minibuffer windows
7f3d5f929d * src/emacs.c (usage_message): Don't mention 'find-file'.
6845282200 Fix a minor inaccuracy in the Emacs manual
74d7bb9498 Fix errors in flyspell-post-command-hook
40fdbb01d0 Work on Tramp's file-truename
1a01423b3c Fix bug with make-directory on MS-Windows root
066efb8666 Fix log-view-diff-common when point is after last entry
3f006b56cd Adapt fileio-tests--symlink-failure to Cygwin
ee512e9a82 Ignore buffers whose name begins with a space in save-some...
9e1b5bd92c Improve tramp-interrupt-process robustness
8d4223e61b Minor Tramp doc update
331d0e520f Fix gensym
466df76f7d Cleanup in files-tests.el
6359fe630a Remove old cl-assert calls in 'newline'
059184e645 Avoid crash with C-g C-g in GC
541006c536 Fix format-time-string %Z bug with negative tz
679e05eeb9 message-citation-line-format %Z is now tz name
4e8888d438 Use doc-view or pdf-tools on any window-system
5f28f0db73 Fix bug with min and max and NaNs
37b5e661d2 Fix recently-introduced copy-directory bug
6bbbc38b34 Merge from Gnulib
57249fb297 Fix compatibility problem in Tramp
411bec82c4 Avoid GCC 7 compilation warning in eval.c
34a6774daa ; Partially revert c3445aed5194

11 files changed, 269 insertions, 63 deletions

diff --git a/src/Makefile.in b/src/Makefile.in
index 0e55ad4bb29..9a8c9c85f04 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -280,7 +280,7 @@ GNU_OBJC_CFLAGS=$(patsubst -specs=%-hardened-cc1,,@GNU_OBJC_CFLAGS@)
 ## w32xfns.o w32select.o image.o w32uniscribe.o if HAVE_W32, else
 ## empty.
 W32_OBJ=@W32_OBJ@
-## -lkernel32 -luser32 -lgdi32 -lole32 -lcomdlg32 lusp10 -lcomctl32
+## -lkernel32 -luser32 -lusp10 -lgdi32 -lole32 -lcomdlg32 -lcomctl32
 ## --lwinspool if HAVE_W32, else empty.
 W32_LIBS=@W32_LIBS@
 
diff --git a/src/data.c b/src/data.c
index 95bf06e5102..e070be6c208 100644
--- a/src/data.c
+++ b/src/data.c
@@ -3010,16 +3010,16 @@ static Lisp_Object
 minmax_driver (ptrdiff_t nargs, Lisp_Object *args,
                enum Arith_Comparison comparison)
 {
-  eassume (0 < nargs);
-  Lisp_Object accum = args[0];  /* pacify GCC */
-  for (ptrdiff_t argnum = 0; argnum < nargs; argnum++)
+  Lisp_Object accum = args[0];
+  CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (accum);
+  for (ptrdiff_t argnum = 1; argnum < nargs; argnum++)
     {
       Lisp_Object val = args[argnum];
       CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (val);
-      if (argnum == 0 || !NILP (arithcompare (val, accum, comparison)))
+      if (!NILP (arithcompare (val, accum, comparison)))
         accum = val;
-      else if (FLOATP (accum) && isnan (XFLOAT_DATA (accum)))
-        return accum;
+      else if (FLOATP (val) && isnan (XFLOAT_DATA (val)))
+        return val;
     }
   return accum;
 }
diff --git a/src/editfns.c b/src/editfns.c
index b03eb947dec..2f8b075817a 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -187,7 +187,8 @@ tzlookup (Lisp_Object zone, bool settz)
                   if (sec != 0)
                     prec += 2, numzone = 100 * numzone + sec;
                 }
-              sprintf (tzbuf, tzbuf_format, prec, numzone,
+              sprintf (tzbuf, tzbuf_format, prec,
+                       XINT (zone) < 0 ? -numzone : numzone,
                        &"-"[XINT (zone) < 0], hour, min, sec);
               zone_string = tzbuf;
             }
diff --git a/src/emacs.c b/src/emacs.c
index 1ad8af70a74..0fe7d9113b4 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -252,7 +252,7 @@ Initialization options:\n\
     "\
 Action options:\n\
 \n\
-FILE                    visit FILE using find-file\n\
+FILE                    visit FILE\n\
 +LINE                   go to line LINE in next FILE\n\
 +LINE:COLUMN            go to line LINE, column COLUMN, in next FILE\n\
 --directory, -L DIR     prepend DIR to load-path (with :DIR, append DIR)\n\
@@ -260,13 +260,13 @@ FILE                    visit FILE using find-file\n\
 --execute EXPR          evaluate Emacs Lisp expression EXPR\n\
 ",
     "\
---file FILE             visit FILE using find-file\n\
---find-file FILE        visit FILE using find-file\n\
+--file FILE             visit FILE\n\
+--find-file FILE        visit FILE\n\
 --funcall, -f FUNC      call Emacs Lisp function FUNC with no arguments\n\
 --insert FILE           insert contents of FILE into current buffer\n\
 --kill                  exit without asking for confirmation\n\
 --load, -l FILE         load Emacs Lisp FILE using the load function\n\
---visit FILE            visit FILE using find-file\n\
+--visit FILE            visit FILE\n\
 \n\
 ",
     "\
diff --git a/src/eval.c b/src/eval.c
index 62e219631db..39d78364d5f 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1428,7 +1428,7 @@ push_handler (Lisp_Object tag_ch_val, enum handlertype handlertype)
 struct handler *
 push_handler_nosignal (Lisp_Object tag_ch_val, enum handlertype handlertype)
 {
-  struct handler *c = handlerlist->nextfree;
+  struct handler *CACHEABLE c = handlerlist->nextfree;
   if (!c)
     {
       c = malloc (sizeof *c);
diff --git a/src/keyboard.c b/src/keyboard.c
index 4db50be855c..e8701b88708 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -5925,7 +5925,10 @@ make_lispy_event (struct input_event *event)
                                       ASIZE (wheel_syms));
         }
 
-        if (event->modifiers & (double_modifier | triple_modifier))
+        if (NUMBERP (event->arg))
+          return list4 (head, position, make_number (double_click_count),
+                        event->arg);
+        else if (event->modifiers & (double_modifier | triple_modifier))
           return list3 (head, position, make_number (double_click_count));
         else
           return list2 (head, position);
diff --git a/src/lcms.c b/src/lcms.c
index f543a030399..a5e527911ef 100644
--- a/src/lcms.c
+++ b/src/lcms.c
@@ -139,6 +139,26 @@ chroma, and hue, respectively. The parameters each default to 1.  */)
   return make_float (cmsCIE2000DeltaE (&Lab1, &Lab2, Kl, Kc, Kh));
 }
 
+static double
+deg2rad (double degrees)
+{
+  return M_PI * degrees / 180.0;
+}
+
+static cmsCIEXYZ illuminant_d65 = { .X = 95.0455, .Y = 100.0, .Z = 108.8753 };
+
+static void
+default_viewing_conditions (const cmsCIEXYZ *wp, cmsViewingConditions *vc)
+{
+  vc->whitePoint.X = wp->X;
+  vc->whitePoint.Y = wp->Y;
+  vc->whitePoint.Z = wp->Z;
+  vc->Yb = 20;
+  vc->La = 100;
+  vc->surround = AVG_SURROUND;
+  vc->D_value = 1.0;
+}
+
 /* FIXME: code duplication */
 
 static bool
@@ -160,11 +180,62 @@ parse_xyz_list (Lisp_Object xyz_list, cmsCIEXYZ *color)
   return true;
 }
 
-DEFUN ("lcms-cam02-ucs", Flcms_cam02_ucs, Slcms_cam02_ucs, 2, 3, 0,
+static bool
+parse_viewing_conditions (Lisp_Object view, const cmsCIEXYZ *wp,
+                          cmsViewingConditions *vc)
+{
+#define PARSE_VIEW_CONDITION_FLOAT(field)                               \
+  if (CONSP (view) && NUMBERP (XCAR (view)))                            \
+    {                                                                   \
+      vc->field = XFLOATINT (XCAR (view));                              \
+      view = XCDR (view);                                               \
+    }                                                                   \
+  else                                                                  \
+    return false;
+#define PARSE_VIEW_CONDITION_INT(field)                                 \
+  if (CONSP (view) && NATNUMP (XCAR (view)))                            \
+    {                                                                   \
+      CHECK_RANGED_INTEGER (XCAR (view), 1, 4);                         \
+      vc->field = XINT (XCAR (view));                                   \
+      view = XCDR (view);                                               \
+    }                                                                   \
+  else                                                                  \
+    return false;
+
+  PARSE_VIEW_CONDITION_FLOAT (Yb);
+  PARSE_VIEW_CONDITION_FLOAT (La);
+  PARSE_VIEW_CONDITION_INT (surround);
+  PARSE_VIEW_CONDITION_FLOAT (D_value);
+
+  if (! NILP (view))
+    return false;
+
+  vc->whitePoint.X = wp->X;
+  vc->whitePoint.Y = wp->Y;
+  vc->whitePoint.Z = wp->Z;
+  return true;
+}
+
+/* References:
+   Li, Luo et al. "The CRI-CAM02UCS colour rendering index." COLOR research
+   and application, 37 No.3, 2012.
+   Luo et al. "Uniform colour spaces based on CIECAM02 colour appearance
+   model." COLOR research and application, 31 No.4, 2006. */
+
+DEFUN ("lcms-cam02-ucs", Flcms_cam02_ucs, Slcms_cam02_ucs, 2, 4, 0,
        doc: /* Compute CAM02-UCS metric distance between COLOR1 and COLOR2.
-Each color is a list of XYZ coordinates, with Y scaled about unity.
-Optional argument is the XYZ white point, which defaults to illuminant D65.  */)
-  (Lisp_Object color1, Lisp_Object color2, Lisp_Object whitepoint)
+Each color is a list of XYZ tristimulus values, with Y scaled about unity.
+Optional argument WHITEPOINT is the XYZ white point, which defaults to
+illuminant D65.
+Optional argument VIEW is a list containing the viewing conditions, and
+is of the form (YB LA SURROUND DVALUE) where SURROUND corresponds to
+  1   AVG_SURROUND
+  2   DIM_SURROUND
+  3   DARK_SURROUND
+  4   CUTSHEET_SURROUND
+The default viewing conditions are (20 100 1 1).  */)
+  (Lisp_Object color1, Lisp_Object color2, Lisp_Object whitepoint,
+   Lisp_Object view)
 {
   cmsViewingConditions vc;
   cmsJCh jch1, jch2;
@@ -188,17 +259,13 @@ Optional argument is the XYZ white point, which defaults to illuminant D65.  */)
   if (!(CONSP (color2) && parse_xyz_list (color2, &xyz2)))
     signal_error ("Invalid color", color2);
   if (NILP (whitepoint))
-    parse_xyz_list (Vlcms_d65_xyz, &xyzw);
+    xyzw = illuminant_d65;
   else if (!(CONSP (whitepoint) && parse_xyz_list (whitepoint, &xyzw)))
     signal_error ("Invalid white point", whitepoint);
-
-  vc.whitePoint.X = xyzw.X;
-  vc.whitePoint.Y = xyzw.Y;
-  vc.whitePoint.Z = xyzw.Z;
-  vc.Yb = 20;
-  vc.La = 100;
-  vc.surround = AVG_SURROUND;
-  vc.D_value = 1.0;
+  if (NILP (view))
+    default_viewing_conditions (&xyzw, &vc);
+  else if (!(CONSP (view) && parse_viewing_conditions (view, &xyzw, &vc)))
+    signal_error ("Invalid view conditions", view);
 
   h1 = cmsCIECAM02Init (0, &vc);
   h2 = cmsCIECAM02Init (0, &vc);
@@ -227,10 +294,10 @@ Optional argument is the XYZ white point, which defaults to illuminant D65.  */)
   Mp2 = 43.86 * log (1.0 + 0.0228 * (jch2.C * sqrt (sqrt (FL))));
   Jp1 = 1.7 * jch1.J / (1.0 + (0.007 * jch1.J));
   Jp2 = 1.7 * jch2.J / (1.0 + (0.007 * jch2.J));
-  ap1 = Mp1 * cos (jch1.h);
-  ap2 = Mp2 * cos (jch2.h);
-  bp1 = Mp1 * sin (jch1.h);
-  bp2 = Mp2 * sin (jch2.h);
+  ap1 = Mp1 * cos (deg2rad (jch1.h));
+  ap2 = Mp2 * cos (deg2rad (jch2.h));
+  bp1 = Mp1 * sin (deg2rad (jch1.h));
+  bp2 = Mp2 * sin (deg2rad (jch2.h));
 
   return make_float (sqrt ((Jp2 - Jp1) * (Jp2 - Jp1) +
                            (ap2 - ap1) * (ap2 - ap1) +
@@ -291,12 +358,6 @@ DEFUN ("lcms2-available-p", Flcms2_available_p, Slcms2_available_p, 0, 0, 0,
 void
 syms_of_lcms2 (void)
 {
-  DEFVAR_LISP ("lcms-d65-xyz", Vlcms_d65_xyz,
-               doc: /* D65 illuminant as a CIE XYZ triple.  */);
-  Vlcms_d65_xyz = list3 (make_float (0.950455),
-                         make_float (1.0),
-                         make_float (1.088753));
-
   defsubr (&Slcms_cie_de2000);
   defsubr (&Slcms_cam02_ucs);
   defsubr (&Slcms2_available_p);
diff --git a/src/nsterm.m b/src/nsterm.m
index 27515335332..f0b6a70dae3 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -1820,8 +1820,8 @@ x_set_window_size (struct frame *f,
 
   if (pixelwise)
     {
-      pixelwidth = width;
-      pixelheight = height;
+      pixelwidth = FRAME_TEXT_TO_PIXEL_WIDTH (f, width);
+      pixelheight = FRAME_TEXT_TO_PIXEL_HEIGHT (f, height);
     }
   else
     {
@@ -6498,24 +6498,139 @@ not_in_argv (NSString *arg)
 
   if ([theEvent type] == NSEventTypeScrollWheel)
     {
-      CGFloat delta = [theEvent deltaY];
-      /* Mac notebooks send wheel events w/delta =0 when trackpad scrolling */
-      if (delta == 0)
+#if defined (NS_IMPL_COCOA) && MAC_OS_X_VERSION_MAX_ALLOWED >= 1070
+#if MAC_OS_X_VERSION_MIN_REQUIRED < 1070
+      if ([theEvent respondsToSelector:@selector(hasPreciseScrollingDeltas)])
         {
-          delta = [theEvent deltaX];
-          if (delta == 0)
+#endif
+          /* If the input device is a touchpad or similar, use precise
+           * scrolling deltas.  These are measured in pixels, so we
+           * have to add them up until they exceed one line height,
+           * then we can send a scroll wheel event.
+           *
+           * If the device only has coarse scrolling deltas, like a
+           * real mousewheel, the deltas represent a ratio of whole
+           * lines, so round up the number of lines.  This means we
+           * always send one scroll event per click, but can still
+           * scroll more than one line if the OS tells us to.
+           */
+          bool horizontal;
+          int lines = 0;
+          int scrollUp = NO;
+
+          /* FIXME: At the top or bottom of the buffer we should
+           * ignore momentum-phase events.  */
+          if (! ns_use_mwheel_momentum
+              && [theEvent momentumPhase] != NSEventPhaseNone)
+            return;
+
+          if ([theEvent hasPreciseScrollingDeltas])
             {
-              NSTRACE_MSG ("deltaIsZero");
-              return;
+              static int totalDeltaX, totalDeltaY;
+              int lineHeight;
+
+              if (NUMBERP (ns_mwheel_line_height))
+                lineHeight = XINT (ns_mwheel_line_height);
+              else
+                {
+                  /* FIXME: Use actual line height instead of the default.  */
+                  lineHeight = default_line_pixel_height
+                    (XWINDOW (FRAME_SELECTED_WINDOW (emacsframe)));
+                }
+
+              if ([theEvent phase] == NSEventPhaseBegan)
+                {
+                  totalDeltaX = 0;
+                  totalDeltaY = 0;
+                }
+
+              totalDeltaX += [theEvent scrollingDeltaX];
+              totalDeltaY += [theEvent scrollingDeltaY];
+
+              /* Calculate the number of lines, if any, to scroll, and
+               * reset the total delta for the direction we're NOT
+               * scrolling so that small movements don't add up.  */
+              if (abs (totalDeltaX) > abs (totalDeltaY)
+                  && abs (totalDeltaX) > lineHeight)
+                {
+                  horizontal = YES;
+                  scrollUp = totalDeltaX > 0;
+
+                  lines = abs (totalDeltaX / lineHeight);
+                  totalDeltaX = totalDeltaX % lineHeight;
+                  totalDeltaY = 0;
+                }
+              else if (abs (totalDeltaY) >= abs (totalDeltaX)
+                       && abs (totalDeltaY) > lineHeight)
+                {
+                  horizontal = NO;
+                  scrollUp = totalDeltaY > 0;
+
+                  lines = abs (totalDeltaY / lineHeight);
+                  totalDeltaY = totalDeltaY % lineHeight;
+                  totalDeltaX = 0;
+                }
+
+              if (lines > 1 && ! ns_use_mwheel_acceleration)
+                lines = 1;
             }
-          emacs_event->kind = HORIZ_WHEEL_EVENT;
+          else
+            {
+              CGFloat delta;
+
+              if ([theEvent scrollingDeltaY] == 0)
+                {
+                  horizontal = YES;
+                  delta = [theEvent scrollingDeltaX];
+                }
+              else
+                {
+                  horizontal = NO;
+                  delta = [theEvent scrollingDeltaY];
+                }
+
+              lines = (ns_use_mwheel_acceleration)
+                ? ceil (fabs (delta)) : 1;
+
+              scrollUp = delta > 0;
+            }
+
+          if (lines == 0)
+            return;
+
+          emacs_event->kind = horizontal ? HORIZ_WHEEL_EVENT : WHEEL_EVENT;
+          emacs_event->arg = (make_number (lines));
+
+          emacs_event->code = 0;
+          emacs_event->modifiers = EV_MODIFIERS (theEvent) |
+            (scrollUp ? up_modifier : down_modifier);
+#if MAC_OS_X_VERSION_MIN_REQUIRED < 1070
         }
       else
-        emacs_event->kind = WHEEL_EVENT;
+#endif
+#endif /* defined (NS_IMPL_COCOA) && MAC_OS_X_VERSION_MAX_ALLOWED >= 1070 */
+#if defined (NS_IMPL_GNUSTEP) || MAC_OS_X_VERSION_MIN_REQUIRED < 1070
+        {
+          CGFloat delta = [theEvent deltaY];
+          /* Mac notebooks send wheel events w/delta =0 when trackpad scrolling */
+          if (delta == 0)
+            {
+              delta = [theEvent deltaX];
+              if (delta == 0)
+                {
+                  NSTRACE_MSG ("deltaIsZero");
+                  return;
+                }
+              emacs_event->kind = HORIZ_WHEEL_EVENT;
+            }
+          else
+            emacs_event->kind = WHEEL_EVENT;
 
-      emacs_event->code = 0;
-      emacs_event->modifiers = EV_MODIFIERS (theEvent) |
-        ((delta > 0) ? up_modifier : down_modifier);
+          emacs_event->code = 0;
+          emacs_event->modifiers = EV_MODIFIERS (theEvent) |
+            ((delta > 0) ? up_modifier : down_modifier);
+        }
+#endif
     }
   else
     {
@@ -6524,9 +6639,11 @@ not_in_argv (NSString *arg)
       emacs_event->modifiers = EV_MODIFIERS (theEvent)
                              | EV_UDMODIFIERS (theEvent);
     }
+
   XSETINT (emacs_event->x, lrint (p.x));
   XSETINT (emacs_event->y, lrint (p.y));
   EV_TRAILER (theEvent);
+  return;
 }
 
 
@@ -6707,9 +6824,10 @@ not_in_argv (NSString *arg)
 
   if (wait_for_tool_bar)
     {
-      /* The toolbar height is always 0 in fullscreen, so don't wait
-         for it to become available. */
+      /* The toolbar height is always 0 in fullscreen and undecorated
+         frames, so don't wait for it to become available. */
       if (FRAME_TOOLBAR_HEIGHT (emacsframe) == 0
+          && FRAME_UNDECORATED (emacsframe) == false
           && ! [self isFullscreen])
         {
           NSTRACE_MSG ("Waiting for toolbar");
@@ -7090,9 +7208,9 @@ not_in_argv (NSString *arg)
 
   win = [[EmacsWindow alloc]
             initWithContentRect: r
-                      styleMask: (FRAME_UNDECORATED (f)
-                                  ? FRAME_UNDECORATED_FLAGS
-                                  : FRAME_DECORATED_FLAGS
+                      styleMask: ((FRAME_UNDECORATED (f)
+                                   ? FRAME_UNDECORATED_FLAGS
+                                   : FRAME_DECORATED_FLAGS)
 #ifdef NS_IMPL_COCOA
                                   | NSWindowStyleMaskResizable
                                   | NSWindowStyleMaskMiniaturizable
@@ -9166,6 +9284,23 @@ Note that this does not apply to images.
 This variable is ignored on Mac OS X < 10.7 and GNUstep.  */);
   ns_use_srgb_colorspace = YES;
 
+  DEFVAR_BOOL ("ns-use-mwheel-acceleration",
+               ns_use_mwheel_acceleration,
+     doc: /*Non-nil means use macOS's standard mouse wheel acceleration.
+This variable is ignored on macOS < 10.7 and GNUstep.  Default is t.  */);
+  ns_use_mwheel_acceleration = YES;
+
+  DEFVAR_LISP ("ns-mwheel-line-height", ns_mwheel_line_height,
+               doc: /*The number of pixels touchpad scrolling considers one line.
+Nil or a non-number means use the default frame line height.
+This variable is ignored on macOS < 10.7 and GNUstep.  Default is nil.  */);
+  ns_mwheel_line_height = Qnil;
+
+  DEFVAR_BOOL ("ns-use-mwheel-momentum", ns_use_mwheel_momentum,
+               doc: /*Non-nil means mouse wheel scrolling uses momentum.
+This variable is ignored on macOS < 10.7 and GNUstep.  Default is t.  */);
+  ns_use_mwheel_momentum = YES;
+
   /* TODO: move to common code */
   DEFVAR_LISP ("x-toolkit-scroll-bars", Vx_toolkit_scroll_bars,
                doc: /* Which toolkit scroll bars Emacs uses, if any.
diff --git a/src/term.c b/src/term.c
index a2ae8c2c6f0..065bce45d3c 100644
--- a/src/term.c
+++ b/src/term.c
@@ -155,12 +155,16 @@ tty_ring_bell (struct frame *f)
 static void
 tty_send_additional_strings (struct terminal *terminal, Lisp_Object sym)
 {
-  Lisp_Object lisp_terminal;
-  Lisp_Object extra_codes;
+  /* Use only accessors like CDR_SAFE and assq_no_quit to avoid any
+     form of quitting or signaling an error, since this function can
+     run as part of the "emergency escape" procedure invoked in the
+     middle of GC, where quitting means crashing (Bug#17406).  */
+  if (! terminal->name)
+    return;
   struct tty_display_info *tty = terminal->display_info.tty;
 
-  XSETTERMINAL (lisp_terminal, terminal);
-  for (extra_codes = Fterminal_parameter (lisp_terminal, sym);
+  for (Lisp_Object extra_codes
+         = CDR_SAFE (assq_no_quit (sym, terminal->param_alist));
        CONSP (extra_codes);
        extra_codes = XCDR (extra_codes))
     {
diff --git a/src/termhooks.h b/src/termhooks.h
index 97c128ba4e2..b5171bf1229 100644
--- a/src/termhooks.h
+++ b/src/termhooks.h
@@ -116,7 +116,9 @@ enum event_kind
                                    .frame_or_window gives the frame
                                    the wheel event occurred in.
                                    .timestamp gives a timestamp (in
-                                   milliseconds) for the event.  */
+                                   milliseconds) for the event.
+                                   .arg may contain the number of
+                                   lines to scroll.  */
   HORIZ_WHEEL_EVENT,            /* A wheel event generated by a second
                                    horizontal wheel that is present on some
                                    mice. See WHEEL_EVENT.  */
diff --git a/src/xdisp.c b/src/xdisp.c
index dc5dbb05762..141275f15a0 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -22395,8 +22395,8 @@ Value is the new character position of point.  */)
             row += dir;
           else
             row -= dir;
-          if (row < MATRIX_FIRST_TEXT_ROW (w->current_matrix)
-              || row > MATRIX_BOTTOM_TEXT_ROW (w->current_matrix, w))
+          if (!(MATRIX_FIRST_TEXT_ROW (w->current_matrix) <= row
+                && row < MATRIX_BOTTOM_TEXT_ROW (w->current_matrix, w)))
             goto simulate_display;
 
           if (dir > 0)