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

1 files changed, 23 insertions, 4 deletions

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);