Merge from origin/emacs-26

11bd8aa24b Fix flymake's loading of subr-x
b500e06f4d Fix Bug#28896
d815de017b Skip a Flymake test for old gcc versions
fd3d8610b2 Make :align-to account for display-line-numbers
831eafc8ae Augment Flymake API for third-party extensions
ddd547fada Improve treatment of Fortran's "class default"
234b1e3864 Flymake backends must check proc obsoleteness in source bu...
3ea6a4d4ba Skip an rsync test in tramp-tests.el
25f83fa7c5 ; Indentation fixes
4d578d432d On Windows default a frame's border width to zero (Bug#28873)
6f1dea5c74 Spelling fixes
b8433b0954 Use pop-to-buffer-same-window instead of switch-to-buffer
2f7163fb72 Fix the MSDOS build.
2551d28fe8 Fix line number display after 'widen'
dc8812829b Remove resizable attribute on macOS undecorated frames (bu...
b970a4a52a Fix handling of `border-width' in `frameset--restore-frame...
445e92658f Mention how to send CC to > 1 address in a bug report
8ca6fa585a Improve format-time-string doc
2e1b3522b8 Improve documentation of 'line-number-display-width'
5b6e59cfdb Implement vc-default-dir-extra-headers for vc-rcs
22adeca42a In NEWS give advice on use of `switch-to-buffer' (Bug#28645)
2c3e6f1ddc Dont update primary selection with winner-undo
b38724ab67 Work around ImageMagick bug 825
20cc68e871 Document rectangle-preview option more (Bug#27974)
a0b7b301dd Do not reject https://gnu.org in commit messages
fb4200a875 Fix Edebug spec for cl-defun (bug#24255)
db68cefe72 Fix errors in kmacro.el post-command-hook
c63b344c3d Fix range-error in image-dired.el
081d2187c4 Fix 'line-number-display-width' in hscrolled windows
16e85456e7 Fix error in tramp-smb-handle-insert-directory
613db8d35c Don't reject PBM header whitespace unnecessarily
3205b12a78 Fix regression in display of PPM images
1ca9ae7069 Require subr-x when compiling nnimap.el
de60992053 Fix ert-test finding by symbol (Bug#28849)
51615a8082 Don't remember old debugger window (Bug#17882)
5980de3727 Disable python native completion on w32 (Bug#28580)
616b4c5956 Let select-frame-by-name choose any frame when called from...
8eb3c01dbd * lisp/dired-aux.el (dired-create-directory): Doc fix.
325dfdae13 Avoid compilation warnings in optimized builds
f79382819c ; * src/composite.c (Fclear_composition_cache): Fix last c...
f95cd5cd70 Improve customization of arabic-shaper-ZWNJ-handling.
a7f154688d Improve customization type of 'mouse-drag-and-drop-region'
864734d112 ; Prefer https: to http: in GNU URLs
3c78960a47 Encourage https: in commit messages
def9715282 ; Cleanup of etc/NEWS
4e59ecc646 Fix wording in Elisp manual's child frames section (Bug#28...
eda9f5018c Another fix for C mode fontification of w32 source files
05aadd8990 Fix fontification of ALIGN_STACK functions
aa0c38f358 Make sure thread stack is properly aligned on MS-Windows
d7038020aa Do not under-align pseudovectors
ff33053012 Fix indentation bug in multi-line CSS selectors
8968be822e ; * etc/NEWS: Grammar and spelling fixes
716b84034d gnutls_mac_get_nonce_size has been added in gnutls 3.3
55e313f7be ; * CONTRIBUTE: More suggestions for using US English.
622c675648 * CONTRIBUTE: Suggest American English.

# Conflicts:
#	etc/NEWS
#	msdos/sed2v2.inp

22 files changed, 220 insertions, 86 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 2e6399e7f8d..da0c3ad4b3e 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -2923,9 +2923,13 @@ set_next_vector (struct Lisp_Vector *v, struct Lisp_Vector *p)
 
 enum
   {
-    /* Alignment of struct Lisp_Vector objects.  */
-    vector_alignment = COMMON_MULTIPLE (FLEXALIGNOF (struct Lisp_Vector),
-                                         GCALIGNMENT),
+    /* Alignment of struct Lisp_Vector objects.  Because pseudovectors
+       can contain any C type, align at least as strictly as
+       max_align_t.  On x86 and x86-64 this can waste up to 8 bytes
+       for typical vectors, since alignof (max_align_t) is 16 but
+       typical vectors need only an alignment of 8.  However, it is
+       not worth the hassle to avoid wasting those bytes.  */
+    vector_alignment = COMMON_MULTIPLE (alignof (max_align_t), GCALIGNMENT),
 
     /* Vector size requests are a multiple of this.  */
     roundup_size = COMMON_MULTIPLE (vector_alignment, word_size)
diff --git a/src/buffer.c b/src/buffer.c
index cc6021bfb5d..1c8b4635086 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -3616,8 +3616,8 @@ void
 fix_start_end_in_overlays (register ptrdiff_t start, register ptrdiff_t end)
 {
   Lisp_Object overlay;
-  struct Lisp_Overlay *before_list;
-  struct Lisp_Overlay *after_list;
+  struct Lisp_Overlay *before_list UNINIT;
+  struct Lisp_Overlay *after_list UNINIT;
   /* These are either nil, indicating that before_list or after_list
      should be assigned, or the cons cell the cdr of which should be
      assigned.  */
diff --git a/src/composite.c b/src/composite.c
index c01e2e3b95c..650bf8708b3 100644
--- a/src/composite.c
+++ b/src/composite.c
@@ -686,6 +686,20 @@ composition_gstring_from_id (ptrdiff_t id)
   return HASH_VALUE (h, id);
 }
 
+DEFUN ("clear-composition-cache", Fclear_composition_cache,
+       Sclear_composition_cache, 0, 0, 0,
+       doc: /* Internal use only.
+Clear composition cache.  */)
+  (void)
+{
+  Lisp_Object args[] = {QCtest, Qequal, QCsize, make_number (311)};
+  gstring_hash_table = CALLMANY (Fmake_hash_table, args);
+  /* Fixme: We call Fclear_face_cache to force complete re-building of
+     display glyphs.  But, it may be better to call this function from
+     Fclear_face_cache instead.  */
+  return Fclear_face_cache (Qt);
+}
+
 bool
 composition_gstring_p (Lisp_Object gstring)
 {
@@ -1982,4 +1996,5 @@ See also the documentation of `auto-composition-mode'.  */);
   defsubr (&Scompose_string_internal);
   defsubr (&Sfind_composition_internal);
   defsubr (&Scomposition_get_gstring);
+  defsubr (&Sclear_composition_cache);
 }
diff --git a/src/conf_post.h b/src/conf_post.h
index febdb8b8bf7..4c9eb32aba3 100644
--- a/src/conf_post.h
+++ b/src/conf_post.h
@@ -31,7 +31,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <stdbool.h>
 
-#if defined DOS_NT && !defined DEFER_MS_W32_H
+#if defined WINDOWSNT && !defined DEFER_MS_W32_H
 # include <ms-w32.h>
 #endif
 
diff --git a/src/data.c b/src/data.c
index 2e7f3e017be..00d1eb43033 100644
--- a/src/data.c
+++ b/src/data.c
@@ -1888,7 +1888,7 @@ Instead, use `add-hook' and specify t for the LOCAL argument.  */)
   (Lisp_Object variable)
 {
   Lisp_Object tem;
-  bool forwarded;
+  bool forwarded UNINIT;
   union Lisp_Val_Fwd valcontents;
   struct Lisp_Symbol *sym;
   struct Lisp_Buffer_Local_Value *blv = NULL;
diff --git a/src/editfns.c b/src/editfns.c
index c00457b0a5c..47ff2a5cbfd 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -2038,11 +2038,11 @@ by text that describes the specified date and time in TIME:
  only blank-padded, %l is like %I blank-padded.
 %p is the locale's equivalent of either AM or PM.
 %q is the calendar quarter (1–4).
-%M is the minute.
-%S is the second.
-%N is the nanosecond, %6N the microsecond, %3N the millisecond, etc.
-%Z is the time zone name, %z is the numeric form.
+%M is the minute (00-59).
+%S is the second (00-59; 00-60 on platforms with leap seconds)
 %s is the number of seconds since 1970-01-01 00:00:00 +0000.
+%N is the nanosecond, %6N the microsecond, %3N the millisecond, etc.
+%Z is the time zone abbreviation, %z is the numeric form.
 
 %c is the locale's date and time format.
 %x is the locale's "preferred" date format.
@@ -2052,7 +2052,8 @@ by text that describes the specified date and time in TIME:
 %R is like "%H:%M", %T is like "%H:%M:%S", %r is like "%I:%M:%S %p".
 %X is the locale's "preferred" time format.
 
-Finally, %n is a newline, %t is a tab, %% is a literal %.
+Finally, %n is a newline, %t is a tab, %% is a literal %, and
+unrecognized %-sequences stand for themselves.
 
 Certain flags and modifiers are available with some format controls.
 The flags are `_', `-', `^' and `#'.  For certain characters X,
diff --git a/src/fileio.c b/src/fileio.c
index ca21b0a115a..ac520c2328e 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -2297,7 +2297,7 @@ This is what happens in interactive use with M-x.  */)
   bool plain_rename = (case_only_rename
                        || (!NILP (ok_if_already_exists)
                            && !INTEGERP (ok_if_already_exists)));
-  int rename_errno;
+  int rename_errno UNINIT;
   if (!plain_rename)
     {
       if (renameat_noreplace (AT_FDCWD, SSDATA (encoded_file),
diff --git a/src/gnutls.c b/src/gnutls.c
index b55d1b9289f..36f65c4acb3 100644
--- a/src/gnutls.c
+++ b/src/gnutls.c
@@ -26,7 +26,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "coding.h"
 #include "buffer.h"
 
-#if 0x030014 <= GNUTLS_VERSION_NUMBER
+#if GNUTLS_VERSION_NUMBER >= 0x030014
 # define HAVE_GNUTLS_X509_SYSTEM_TRUST
 #endif
 
@@ -36,10 +36,16 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
    The relevant fix seems to have been made in GnuTLS 3.5.1; see:
    https://gitlab.com/gnutls/gnutls/commit/568935848dd6b82b9315d8b6c529d00e2605e03d
    So, require 3.5.1.  */
-#if 0x030501 <= GNUTLS_VERSION_NUMBER
+#if GNUTLS_VERSION_NUMBER >= 0x030501
 # define HAVE_GNUTLS_AEAD
 #endif
 
+/* gnutls_mac_get_nonce_size was added in GnuTLS 3.2.0, but was
+   exported only since 3.3.0. */
+#if GNUTLS_VERSION_NUMBER >= 0x030300
+# define HAVE_GNUTLS_MAC_GET_NONCE_SIZE
+#endif
+
 #ifdef HAVE_GNUTLS
 
 # ifdef WINDOWSNT
@@ -187,7 +193,9 @@ DEF_DLL_FN (const char *, gnutls_mac_get_name, (gnutls_mac_algorithm_t));
 #  ifdef HAVE_GNUTLS3
 DEF_DLL_FN (int, gnutls_rnd, (gnutls_rnd_level_t, void *, size_t));
 DEF_DLL_FN (const gnutls_mac_algorithm_t *, gnutls_mac_list, (void));
+#   ifdef HAVE_GNUTLS_MAC_GET_NONCE_SIZE
 DEF_DLL_FN (size_t, gnutls_mac_get_nonce_size, (gnutls_mac_algorithm_t));
+#   endif
 DEF_DLL_FN (size_t, gnutls_mac_get_key_size, (gnutls_mac_algorithm_t));
 DEF_DLL_FN (const gnutls_digest_algorithm_t *, gnutls_digest_list, (void));
 DEF_DLL_FN (const char *, gnutls_digest_get_name, (gnutls_digest_algorithm_t));
@@ -316,7 +324,9 @@ init_gnutls_functions (void)
 #  ifdef HAVE_GNUTLS3
   LOAD_DLL_FN (library, gnutls_rnd);
   LOAD_DLL_FN (library, gnutls_mac_list);
+#   ifdef HAVE_GNUTLS_MAC_GET_NONCE_SIZE
   LOAD_DLL_FN (library, gnutls_mac_get_nonce_size);
+#   endif
   LOAD_DLL_FN (library, gnutls_mac_get_key_size);
   LOAD_DLL_FN (library, gnutls_digest_list);
   LOAD_DLL_FN (library, gnutls_digest_get_name);
@@ -427,7 +437,9 @@ init_gnutls_functions (void)
 #  ifdef HAVE_GNUTLS3
 #  define gnutls_rnd fn_gnutls_rnd
 #  define gnutls_mac_list fn_gnutls_mac_list
-#  define gnutls_mac_get_nonce_size fn_gnutls_mac_get_nonce_size
+#   ifdef HAVE_GNUTLS_MAC_GET_NONCE_SIZE
+#    define gnutls_mac_get_nonce_size fn_gnutls_mac_get_nonce_size
+#   endif
 #  define gnutls_mac_get_key_size fn_gnutls_mac_get_key_size
 #  define gnutls_digest_list fn_gnutls_digest_list
 #  define gnutls_digest_get_name fn_gnutls_digest_get_name
@@ -442,10 +454,10 @@ init_gnutls_functions (void)
 #  define gnutls_cipher_decrypt2 fn_gnutls_cipher_decrypt2
 #  define gnutls_cipher_deinit fn_gnutls_cipher_deinit
 #   ifdef HAVE_GNUTLS_AEAD
-#  define gnutls_aead_cipher_encrypt fn_gnutls_aead_cipher_encrypt
-#  define gnutls_aead_cipher_decrypt fn_gnutls_aead_cipher_decrypt
-#  define gnutls_aead_cipher_init fn_gnutls_aead_cipher_init
-#  define gnutls_aead_cipher_deinit fn_gnutls_aead_cipher_deinit
+#    define gnutls_aead_cipher_encrypt fn_gnutls_aead_cipher_encrypt
+#    define gnutls_aead_cipher_decrypt fn_gnutls_aead_cipher_decrypt
+#    define gnutls_aead_cipher_init fn_gnutls_aead_cipher_init
+#    define gnutls_aead_cipher_deinit fn_gnutls_aead_cipher_deinit
 #   endif
 #  define gnutls_hmac_init fn_gnutls_hmac_init
 #  define gnutls_hmac_get_len fn_gnutls_hmac_get_len
@@ -2178,6 +2190,10 @@ name. */)
       /* A symbol representing the GnuTLS MAC algorithm.  */
       Lisp_Object gma_symbol = intern (gnutls_mac_get_name (gma));
 
+      size_t nonce_size = 0;
+#ifdef HAVE_GNUTLS_MAC_GET_NONCE_SIZE
+      nonce_size = gnutls_mac_get_nonce_size (gma);
+#endif
       Lisp_Object mp = listn (CONSTYPE_HEAP, 11, gma_symbol,
                               QCmac_algorithm_id, make_number (gma),
                               QCtype, Qgnutls_type_mac_algorithm,
@@ -2189,7 +2205,7 @@ name. */)
                               make_number (gnutls_mac_get_key_size (gma)),
 
                               QCmac_algorithm_noncesize,
-                              make_number (gnutls_mac_get_nonce_size (gma)));
+                              make_number (nonce_size));
       mac_algorithms = Fcons (mp, mac_algorithms);
     }
 
diff --git a/src/image.c b/src/image.c
index 3dac7086cb4..c1c1671899b 100644
--- a/src/image.c
+++ b/src/image.c
@@ -2574,7 +2574,7 @@ xbm_image_p (Lisp_Object object)
 static int
 xbm_scan (char **s, char *end, char *sval, int *ival)
 {
-  unsigned char c;
+  unsigned char c UNINIT;
 
  loop:
 
@@ -5277,6 +5277,25 @@ pbm_scan_number (char **s, char *end)
   return val;
 }
 
+/* Scan an index from *S and return it.  It is a one-byte unsigned
+   index if !TWO_BYTE, and a two-byte big-endian unsigned index if
+   TWO_BYTE.  */
+
+static int
+pbm_scan_index (char **s, bool two_byte)
+{
+  char *p = *s;
+  unsigned char c0 = *p++;
+  int n = c0;
+  if (two_byte)
+    {
+      unsigned char c1 = *p++;
+      n = (n << 8) + c1;
+    }
+  *s = p;
+  return n;
+}
+
 
 /* Load PBM image IMG for use on frame F.  */
 
@@ -5499,7 +5518,8 @@ pbm_load (struct frame *f, struct image *img)
   else
     {
       int expected_size = height * width;
-      if (max_color_idx > 255)
+      bool two_byte = 255 < max_color_idx;
+      if (two_byte)
         expected_size *= 2;
       if (type == PBM_COLOR)
         expected_size *= 3;
@@ -5522,24 +5542,14 @@ pbm_load (struct frame *f, struct image *img)
             int r, g, b;
 
             if (type == PBM_GRAY && raw_p)
-              {
-                r = g = b = *p++;
-                if (max_color_idx > 255)
-                  r = g = b = r * 256 + *p++;
-              }
+              r = g = b = pbm_scan_index (&p, two_byte);
             else if (type == PBM_GRAY)
               r = g = b = pbm_scan_number (&p, end);
             else if (raw_p)
               {
-                r = *p++;
-                if (max_color_idx > 255)
-                  r = r * 256 + *p++;
-                g = *p++;
-                if (max_color_idx > 255)
-                  g = g * 256 + *p++;
-                b = *p++;
-                if (max_color_idx > 255)
-                  b = b * 256 + *p++;
+                r = pbm_scan_index (&p, two_byte);
+                g = pbm_scan_index (&p, two_byte);
+                b = pbm_scan_index (&p, two_byte);
               }
             else
               {
@@ -7839,7 +7849,7 @@ gif_load (struct frame *f, struct image *img)
   init_color_table ();
 
 #ifndef USE_CAIRO
-  unsigned long bgcolor;
+  unsigned long bgcolor UNINIT;
   if (STRINGP (specified_bg))
     bgcolor = x_alloc_image_color (f, img, specified_bg,
                                    FRAME_BACKGROUND_PIXEL (f));
@@ -8542,13 +8552,19 @@ imagemagick_load_image (struct frame *f, struct image *img,
   char hint_buffer[MaxTextExtent];
   char *filename_hint = NULL;
 
+  /* Initialize the ImageMagick environment.  */
+  static bool imagemagick_initialized;
+  if (!imagemagick_initialized)
+    {
+      imagemagick_initialized = true;
+      MagickWandGenesis ();
+    }
+
   /* Handle image index for image types who can contain more than one image.
      Interface :index is same as for GIF.  First we "ping" the image to see how
      many sub-images it contains.  Pinging is faster than loading the image to
      find out things about it.  */
 
-  /* Initialize the imagemagick environment.  */
-  MagickWandGenesis ();
   image = image_spec_value (img->spec, QCindex, NULL);
   ino = INTEGERP (image) ? XFASTINT (image) : 0;
   image_wand = NewMagickWand ();
@@ -8849,8 +8865,10 @@ imagemagick_load_image (struct frame *f, struct image *img,
   DestroyMagickWand (image_wand);
   if (bg_wand) DestroyPixelWand (bg_wand);
 
-  /* `MagickWandTerminus' terminates the imagemagick environment.  */
-  MagickWandTerminus ();
+  /* Do not call MagickWandTerminus, to work around ImageMagick bug 825.  See:
+     https://github.com/ImageMagick/ImageMagick/issues/825
+     Although this bug was introduced in ImageMagick 6.9.9-14 and
+     fixed in 6.9.9-18, it's simpler to work around it in all versions.  */
 
   return 1;
 
@@ -8858,7 +8876,6 @@ imagemagick_load_image (struct frame *f, struct image *img,
   DestroyMagickWand (image_wand);
   if (bg_wand) DestroyPixelWand (bg_wand);
 
-  MagickWandTerminus ();
   /* TODO more cleanup.  */
   image_error ("Error parsing IMAGEMAGICK image `%s'", img->spec);
   return 0;
diff --git a/src/indent.c b/src/indent.c
index 26507b5eb5b..192eec72efe 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -1974,6 +1974,11 @@ line_number_display_width (struct window *w, int *width, int *pixel_width)
           saved_restriction = true;
         }
       start_display (&it, w, wstart);
+      /* The call to move_it_by_lines below will not generate a line
+         number if the first line shown in the window is hscrolled
+         such that all of its display elements are out of view.  So we
+         pretend the hscroll doesn't exist.  */
+      it.first_visible_x = 0;
       move_it_by_lines (&it, 1);
       *width = it.lnum_width;
       *pixel_width = it.lnum_pixel_width;
@@ -1986,14 +1991,26 @@ line_number_display_width (struct window *w, int *width, int *pixel_width)
 DEFUN ("line-number-display-width", Fline_number_display_width,
        Sline_number_display_width, 0, 1, 0,
        doc: /* Return the width used for displaying line numbers in the selected window.
-If optional argument PIXELWISE is non-nil, return the width in pixels,
-otherwise return the width in columns of the face used to display
-line numbers, `line-number'.  */)
+If optional argument PIXELWISE is the symbol `columns', return the width
+in units of the frame's canonical character width.  In this case, the
+value is a float.
+If optional argument PIXELWISE is t or any other non-nil value, return
+the width as an integer number of pixels.
+Otherwise return the value as an integer number of columns of the face
+used to display line numbers, `line-number'.  Note that in the latter
+case, the value doesn't include the 2 columns used for padding the
+numbers on display.  */)
   (Lisp_Object pixelwise)
 {
   int width, pixel_width;
+  struct window *w = XWINDOW (selected_window);
   line_number_display_width (XWINDOW (selected_window), &width, &pixel_width);
-  if (!NILP (pixelwise))
+  if (EQ (pixelwise, Qcolumns))
+    {
+      struct frame *f = XFRAME (w->frame);
+      return make_float ((double) pixel_width / FRAME_COLUMN_WIDTH (f));
+    }
+  else if (!NILP (pixelwise))
     return make_number (pixel_width);
   return make_number (width);
 }
@@ -2355,6 +2372,8 @@ syms_of_indent (void)
                doc: /* Indentation can insert tabs if this is non-nil.  */);
   indent_tabs_mode = 1;
 
+  DEFSYM (Qcolumns, "columns");
+
   defsubr (&Scurrent_indentation);
   defsubr (&Sindent_to);
   defsubr (&Scurrent_column);
diff --git a/src/msdos.c b/src/msdos.c
index a8aef9ac405..f7c99f63fff 100644
--- a/src/msdos.c
+++ b/src/msdos.c
@@ -3943,6 +3943,8 @@ careadlinkat (int fd, char const *filename,
 int
 faccessat (int dirfd, const char * path, int mode, int flags)
 {
+  char fullname[MAXPATHLEN];
+
   /* We silently ignore FLAGS.  */
   flags = flags;
 
diff --git a/src/msdos.h b/src/msdos.h
index 16292c551d9..e4f633e9df4 100644
--- a/src/msdos.h
+++ b/src/msdos.h
@@ -21,6 +21,8 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <dpmi.h>
 
+#include "termhooks.h"          /* struct terminal */
+
 int dos_ttraw (struct tty_display_info *);
 int dos_ttcooked (void);
 int dos_get_saved_screen (char **, int *, int *);
@@ -67,6 +69,7 @@ void syms_of_win16select (void);
 
 /* Constants.  */
 #define EINPROGRESS 112
+#define ENOTSUP     ENOSYS
 /* Gnulib sets O_CLOEXEC to O_NOINHERIT, which gets in the way when we
    need to redirect standard handles for subprocesses using temporary
    files created by mkostemp, see callproc.c.  */
diff --git a/src/nsterm.m b/src/nsterm.m
index 0b43c04c0b7..709e905ec8f 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -423,20 +423,12 @@ static CGPoint menu_mouse_point;
     }
 
 
-/* GNUstep always shows decorations if the window is resizable,
-   miniaturizable or closable, but Cocoa does strange things in native
-   fullscreen mode if you don't have at least resizable enabled.
-
-   These flags will be OR'd or XOR'd with the NSWindow's styleMask
+/* These flags will be OR'd or XOR'd with the NSWindow's styleMask
    property depending on what we're doing. */
-#ifdef NS_IMPL_COCOA
-#define FRAME_DECORATED_FLAGS NSWindowStyleMaskTitled
-#else
 #define FRAME_DECORATED_FLAGS (NSWindowStyleMaskTitled              \
                                | NSWindowStyleMaskResizable         \
                                | NSWindowStyleMaskMiniaturizable    \
                                | NSWindowStyleMaskClosable)
-#endif
 #define FRAME_UNDECORATED_FLAGS NSWindowStyleMaskBorderless
 
 /* TODO: get rid of need for these forward declarations */
@@ -7211,15 +7203,9 @@ not_in_argv (NSString *arg)
 
   win = [[EmacsWindow alloc]
             initWithContentRect: r
-                      styleMask: ((FRAME_UNDECORATED (f)
-                                   ? FRAME_UNDECORATED_FLAGS
-                                   : FRAME_DECORATED_FLAGS)
-#ifdef NS_IMPL_COCOA
-                                  | NSWindowStyleMaskResizable
-                                  | NSWindowStyleMaskMiniaturizable
-                                  | NSWindowStyleMaskClosable
-#endif
-                                  )
+                      styleMask: (FRAME_UNDECORATED (f)
+                                  ? FRAME_UNDECORATED_FLAGS
+                                  : FRAME_DECORATED_FLAGS)
                         backing: NSBackingStoreBuffered
                           defer: YES];
 
diff --git a/src/process.c b/src/process.c
index 05feba73253..fc46e743328 100644
--- a/src/process.c
+++ b/src/process.c
@@ -40,6 +40,8 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
+#endif  /* subprocesses */
+
 #ifdef HAVE_SETRLIMIT
 # include <sys/resource.h>
 
@@ -49,6 +51,8 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 static struct rlimit nofile_limit;
 #endif
 
+#ifdef subprocesses
+
 /* Are local (unix) sockets supported?  */
 #if defined (HAVE_SYS_UN_H)
 #if !defined (AF_LOCAL) && defined (AF_UNIX)
@@ -3830,7 +3834,7 @@ usage: (make-network-process &rest ARGS)  */)
   Lisp_Object proc;
   Lisp_Object contact;
   struct Lisp_Process *p;
-  const char *portstring;
+  const char *portstring UNINIT;
   ptrdiff_t portstringlen ATTRIBUTE_UNUSED;
   char portbuf[INT_BUFSIZE_BOUND (EMACS_INT)];
 #ifdef HAVE_LOCAL_SOCKETS
@@ -7455,6 +7459,13 @@ keyboard_bit_set (fd_set *mask)
 
 #else  /* not subprocesses */
 
+/* This is referenced in thread.c:run_thread (which is never actually
+   called, since threads are not enabled for this configuration.  */
+void
+update_processes_for_thread_death (Lisp_Object dying_thread)
+{
+}
+
 /* Defined in msdos.c.  */
 extern int sys_select (int, fd_set *, fd_set *, fd_set *,
                        struct timespec *, void *);
diff --git a/src/sysdep.c b/src/sysdep.c
index dd0062b6f04..f9cc2c81762 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -831,6 +831,8 @@ unblock_child_signal (sigset_t const *oldset)
   pthread_sigmask (SIG_SETMASK, oldset, 0);
 }
 
+#endif  /* !MSDOS */
+
 /* Block SIGINT.  */
 void
 block_interrupt_signal (sigset_t *oldset)
@@ -848,7 +850,6 @@ restore_signal_mask (sigset_t const *oldset)
   pthread_sigmask (SIG_SETMASK, oldset, 0);
 }
 
-#endif  /* !MSDOS */
 
 /* Saving and restoring the process group of Emacs's terminal.  */
 
diff --git a/src/sysselect.h b/src/sysselect.h
index 8295aeb8421..4d8a4d0a3a9 100644
--- a/src/sysselect.h
+++ b/src/sysselect.h
@@ -50,6 +50,11 @@ typedef int fd_set;
 #endif
 
 #ifdef MSDOS
+/* The above #define for 'select' gets in the way because sysselect.h
+   is included in thread.h, which is included everywhere, and 'select'
+   declared in DJGPP system headers has a signature incompatible with
+   'pselect', which we emulate in msdos.c.  */
+#undef select
 #define pselect sys_select
 #endif
 
diff --git a/src/systhread.c b/src/systhread.c
index ee89a1ed3ff..6f9baabaf2e 100644
--- a/src/systhread.c
+++ b/src/systhread.c
@@ -187,7 +187,7 @@ sys_thread_yield (void)
 
 #elif defined (WINDOWSNT)
 
-#include <windows.h>
+#include <w32term.h>
 
 /* Cannot include <process.h> because of the local header by the same
    name, sigh.  */
@@ -326,8 +326,9 @@ sys_thread_self (void)
 static thread_creation_function *thread_start_address;
 
 /* _beginthread wants a void function, while we are passed a function
-   that returns a pointer.  So we use a wrapper.  */
-static void
+   that returns a pointer.  So we use a wrapper.  See the command in
+   w32term.h about the need for ALIGN_STACK attribute.  */
+static void ALIGN_STACK
 w32_beginthread_wrapper (void *arg)
 {
   (void)thread_start_address (arg);
diff --git a/src/thread.c b/src/thread.c
index d075bdb3a13..c03cdda0fae 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -806,7 +806,11 @@ If NAME is given, it must be a string; it names the new thread.  */)
     {
       /* Restore the previous situation.  */
       all_threads = all_threads->next_thread;
+#ifdef THREADS_ENABLED
       error ("Could not start a new thread");
+#else
+      error ("Concurrency is not supported in this configuration");
+#endif
     }
 
   /* FIXME: race here where new thread might not be filled in?  */
diff --git a/src/thread.h b/src/thread.h
index cb2133d72d4..19baafbf8a1 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -25,6 +25,10 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include <sys/socket.h>
 #endif
 
+#ifdef MSDOS
+#include <signal.h>             /* sigset_t */
+#endif
+
 #include "sysselect.h"          /* FIXME */
 #include "systime.h"            /* FIXME */
 #include "systhread.h"
diff --git a/src/w32fns.c b/src/w32fns.c
index e3de22d68ab..d2d4b2c7355 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -5847,7 +5847,8 @@ This function is an internal primitive--use `make-frame' instead.  */)
      that are needed to determine window geometry.  */
   x_default_font_parameter (f, parameters);
 
-  x_default_parameter (f, parameters, Qborder_width, make_number (2),
+  /* Default BorderWidth to 0 to match other platforms.  */
+  x_default_parameter (f, parameters, Qborder_width, make_number (0),
                        "borderWidth", "BorderWidth", RES_TYPE_NUMBER);
 
   /* We recognize either internalBorderWidth or internalBorder
@@ -5862,7 +5863,7 @@ This function is an internal primitive--use `make-frame' instead.  */)
         parameters = Fcons (Fcons (Qinternal_border_width, value),
                             parameters);
     }
-  /* Default internalBorderWidth to 0 on Windows to match other programs.  */
+
   x_default_parameter (f, parameters, Qinternal_border_width, make_number (0),
                        "internalBorderWidth", "InternalBorder", RES_TYPE_NUMBER);
   x_default_parameter (f, parameters, Qright_divider_width, make_number (0),
diff --git a/src/w32term.h b/src/w32term.h
index 16b44b0ca2f..8d08ca0a2bf 100644
--- a/src/w32term.h
+++ b/src/w32term.h
@@ -22,13 +22,14 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "frame.h"
 #include "atimer.h"
 
-/* Stack alignment stuff.  Every CALLBACK function should have the
-   ALIGN_STACK attribute if it manipulates Lisp objects, because
-   Windows x86 32-bit ABI only guarantees 4-byte stack alignment, and
-   that is what we will get when a Windows function calls us.  The
-   ALIGN_STACK attribute forces GCC to emit a preamble code to
-   re-align the stack at function entry.  Further details about this
-   can be found in http://www.peterstock.co.uk/games/mingw_sse/.  */
+/* Stack alignment stuff.  Every CALLBACK and thread function should
+   have the ALIGN_STACK attribute if it manipulates Lisp objects,
+   because Windows x86 32-bit ABI only guarantees 4-byte stack
+   alignment, and that is what we will get when a Windows function
+   calls us.  The ALIGN_STACK attribute forces GCC to emit a preamble
+   code to re-align the stack at function entry.  Further details
+   about this can be found in
+   http://www.peterstock.co.uk/games/mingw_sse/.  */
 #ifdef __GNUC__
 # if USE_STACK_LISP_OBJECTS && !defined _WIN64 && !defined __x86_64__   \
   && __GNUC__ + (__GNUC_MINOR__ > 1) >= 5
diff --git a/src/xdisp.c b/src/xdisp.c
index b14b7daf2b0..dc23959aadb 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -20889,9 +20889,11 @@ maybe_produce_line_number (struct it *it)
               && it->w->base_line_pos <= IT_CHARPOS (*it)
               /* line-number-mode always displays narrowed line
                  numbers, so we cannot use its data if the user wants
-                 line numbers that disregard narrowing.  */
+                 line numbers that disregard narrowing, or if the
+                 buffer's narrowing has just changed.  */
               && !(display_line_numbers_widen
-                   && (BEG_BYTE != BEGV_BYTE || Z_BYTE != ZV_BYTE)))
+                   && (BEG_BYTE != BEGV_BYTE || Z_BYTE != ZV_BYTE))
+              && !current_buffer->clip_changed)
             {
               start_from = CHAR_TO_BYTE (it->w->base_line_pos);
               last_line = it->w->base_line_number - 1;
@@ -25121,7 +25123,20 @@ else if the text is replaced by an ellipsis.  */)
      '(space :width (+ left-fringe left-margin (- (1))))
      '(space :width (+ left-fringe left-margin (-1)))
 
-*/
+   If ALIGN_TO is NULL, returns the result in *RES.  If ALIGN_TO is
+   non-NULL, the value of *ALIGN_TO is a window-relative pixel
+   coordinate, and *RES is the additional pixel width from that point
+   till the end of the stretch glyph.
+
+   WIDTH_P non-zero means take the width dimension or X coordinate of
+   the object specified by PROP, WIDTH_P zero means take the height
+   dimension or the Y coordinate.  (Therefore, if ALIGN_TO is
+   non-NULL, WIDTH_P should be non-zero.)
+
+   FONT is the font of the face of the surrounding text.
+
+   The return value is non-zero if width or height were successfully
+   calculated, i.e. if PROP is a valid spec.  */
 
 static bool
 calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
@@ -25143,6 +25158,7 @@ calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
         {
           char *unit = SSDATA (SYMBOL_NAME (prop));
 
+          /* The UNIT expression, e.g. as part of (NUM . UNIT).  */
           if (unit[0] == 'i' && unit[1] == 'n')
             pixels = 1.0;
           else if (unit[0] == 'm' && unit[1] == 'm')
@@ -25163,10 +25179,12 @@ calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
         }
 
 #ifdef HAVE_WINDOW_SYSTEM
+      /* 'height': the height of FONT.  */
       if (EQ (prop, Qheight))
         return OK_PIXELS (font
                           ? normal_char_height (font, -1)
                           : FRAME_LINE_HEIGHT (it->f));
+      /* 'width': the width of FONT.  */
       if (EQ (prop, Qwidth))
         return OK_PIXELS (font
                           ? FONT_WIDTH (font)
@@ -25176,33 +25194,48 @@ calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
         return OK_PIXELS (1);
 #endif
 
+      /* 'text': the width or height of the text area.  */
       if (EQ (prop, Qtext))
           return OK_PIXELS (width_p
-                            ? window_box_width (it->w, TEXT_AREA)
+                            ? (window_box_width (it->w, TEXT_AREA)
+                               - it->lnum_pixel_width)
                             : WINDOW_BOX_HEIGHT_NO_MODE_LINE (it->w));
 
+      /* ':align_to'.  First time we compute the value, window
+         elements are interpreted as the position of the element's
+         left edge.  */
       if (align_to && *align_to < 0)
         {
           *res = 0;
+          /* 'left': left edge of the text area.  */
           if (EQ (prop, Qleft))
-            return OK_ALIGN_TO (window_box_left_offset (it->w, TEXT_AREA));
+            return OK_ALIGN_TO (window_box_left_offset (it->w, TEXT_AREA)
+                                + it->lnum_pixel_width);
+          /* 'right': right edge of the text area.  */
           if (EQ (prop, Qright))
             return OK_ALIGN_TO (window_box_right_offset (it->w, TEXT_AREA));
+          /* 'center': the center of the text area.  */
           if (EQ (prop, Qcenter))
             return OK_ALIGN_TO (window_box_left_offset (it->w, TEXT_AREA)
+                                + it->lnum_pixel_width
                                 + window_box_width (it->w, TEXT_AREA) / 2);
+          /* 'left-fringe': left edge of the left fringe.  */
           if (EQ (prop, Qleft_fringe))
             return OK_ALIGN_TO (WINDOW_HAS_FRINGES_OUTSIDE_MARGINS (it->w)
                                 ? WINDOW_LEFT_SCROLL_BAR_AREA_WIDTH (it->w)
                                 : window_box_right_offset (it->w, LEFT_MARGIN_AREA));
+          /* 'right-fringe': left edge of the right fringe.  */
           if (EQ (prop, Qright_fringe))
             return OK_ALIGN_TO (WINDOW_HAS_FRINGES_OUTSIDE_MARGINS (it->w)
                                 ? window_box_right_offset (it->w, RIGHT_MARGIN_AREA)
                                 : window_box_right_offset (it->w, TEXT_AREA));
+          /* 'left-margin': left edge of the left display margin.  */
           if (EQ (prop, Qleft_margin))
             return OK_ALIGN_TO (window_box_left_offset (it->w, LEFT_MARGIN_AREA));
+          /* 'right-margin': left edge of the right display margin.  */
           if (EQ (prop, Qright_margin))
             return OK_ALIGN_TO (window_box_left_offset (it->w, RIGHT_MARGIN_AREA));
+          /* 'scroll-bar': left edge of the vertical scroll bar.  */
           if (EQ (prop, Qscroll_bar))
             return OK_ALIGN_TO (WINDOW_HAS_VERTICAL_SCROLL_BAR_ON_LEFT (it->w)
                                 ? 0
@@ -25213,6 +25246,7 @@ calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
         }
       else
         {
+          /* Otherwise, the elements stand for their width.  */
           if (EQ (prop, Qleft_fringe))
             return OK_PIXELS (WINDOW_LEFT_FRINGE_WIDTH (it->w));
           if (EQ (prop, Qright_fringe))
@@ -25235,6 +25269,8 @@ calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
       int base_unit = (width_p
                        ? FRAME_COLUMN_WIDTH (it->f)
                        : FRAME_LINE_HEIGHT (it->f));
+      if (width_p && align_to && *align_to < 0)
+        return OK_PIXELS (XFLOATINT (prop) * base_unit + it->lnum_pixel_width);
       return OK_PIXELS (XFLOATINT (prop) * base_unit);
     }
 
@@ -25246,6 +25282,7 @@ calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
       if (SYMBOLP (car))
         {
 #ifdef HAVE_WINDOW_SYSTEM
+          /* '(image PROPS...)': width or height of the specified image.  */
           if (FRAME_WINDOW_P (it->f)
               && valid_image_p (prop))
             {
@@ -25254,12 +25291,15 @@ calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
 
               return OK_PIXELS (width_p ? img->width : img->height);
             }
+          /* '(xwidget PROPS...)': dimensions of the specified xwidget.  */
           if (FRAME_WINDOW_P (it->f) && valid_xwidget_spec_p (prop))
             {
               /* TODO: Don't return dummy size.  */
               return OK_PIXELS (100);
             }
 #endif
+          /* '(+ EXPR...)' or '(- EXPR...)' add or subtract
+             recursively calculated values.  */
           if (EQ (car, Qplus) || EQ (car, Qminus))
             {
               bool first = true;
@@ -25287,15 +25327,18 @@ calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
             car = Qnil;
         }
 
+      /* '(NUM)': absolute number of pixels.  */
       if (NUMBERP (car))
         {
           double fact;
+          int offset =
+            width_p && align_to && *align_to < 0 ? it->lnum_pixel_width : 0;
           pixels = XFLOATINT (car);
           if (NILP (cdr))
-            return OK_PIXELS (pixels);
+            return OK_PIXELS (pixels + offset);
           if (calc_pixel_width_or_height (&fact, it, cdr,
                                           font, width_p, align_to))
-            return OK_PIXELS (pixels * fact);
+            return OK_PIXELS (pixels * fact + offset);
           return false;
         }