Merge from origin/emacs-25

c3489d0 * lisp/w32-fns.el (set-message-beep, w32-get-locale-info) (w3...
a4d882c Correct old cell name unbinding when renaming cell.
6c12c53 Merge branch 'emacs-25' of git.sv.gnu.org:/srv/git/emacs into...
0be6725 Document problem: slow screen refresh on missing font.
853b9b9 * admin/admin.el (add-release-logs): Basic check of existing ...
5fa80cf * build-aux/gitlog-to-emacslog: Handle empty generated Change...
3c79e51 * admin/admin.el (add-release-logs): Generate ChangeLog if ne...
42275df * doc/misc/texinfo.tex: Revert previous change (Bug#23611).
3f4a9d9 * admin/authors.el (authors): First update the ChangeLog.
897fb6f ; 'Changes from the pre-25.1 API' copyedits
825ca25 Rename vc-stay-local back to vc-cvs-stay-local
4efb3e8 * doc/emacs/files.texi (Comparing Files): * doc/emacs/trouble...
b995d1e * doc/misc/eww.texi (Advanced): Fix xref.
2e589c0 Fix cross-references between manuals
f3d2ded * doc/misc/vhdl-mode.texi (Sample Init File): Rename node to ...
906c810 ; * admin/release-process: Move etc/HISTORY from here... ; * ...
bea1b65 * admin/admin.el (add-release-logs): Also update etc/HISTORY.
503e752 ; * CONTRIBUTE: Fix a typo.
fbfd478 Avoid aborting due to errors in arguments of 'set-face-attrib...
bdfbe6d ; * admin/release-process: Copyedits.
44a6aed ; * test/automated/data-tests.el: Standardize license notice.
c33ed39 ; * test/automated/viper-tests.el: Standardize license notice.
df4a14b Add automated test for viper-tests.el
c0139e3 Fix viper undo breakage from undo-boundary changes
920d76c Fix reference to obsolete fn ps-eval-switch
18a9bc1 Do not trash symlinks to init file
2671179 Don't print the "decomposition" line for control chars in wha...
869092c Bring back xterm pasting with middle mouse
5ab0830 Provide workaround for xftfont rendering problem
c9f7ec7 * lisp/desktop.el: Disable restore frameset if in non-graphic...
30989a0 Mention GTK+ problems in etc/PROBLEMS
421e3c4 * lisp/emacs-lisp/package.el (package-refresh-contents):
dadfc30 Revert "epg: Add a way to detect gpg1 executable for tests"
e41a5cb Avoid errors with Czech and Slovak input methods
d4ae6d7 epg: Add a way to detect gpg1 executable for tests
ebc3a94 * lisp/emacs-lisp/package.el: Fix free variable warnings.
6e71295 * lisp/emacs-lisp/package.el (package--with-response-buffer):
c45d9f6 Improve documentation of 'server-name'
3b5e38c Modernize ASLR advice in etc/PROBLEMS
1fe1e0a * lisp/char-fold.el: Rename from character-fold.el.

2 files changed, 81 insertions, 33 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 4e8567e2fdb..d1eadd56a21 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1110,11 +1110,11 @@ as many other symbols like U+249C (PARENTHESIZED LATIN SMALL LETTER
 A).
 
 Character folding is enabled by customizing 'search-default-mode' to
-the value 'character-fold-to-regexp'.  You can also toggle character
+the value 'char-fold-to-regexp'.  You can also toggle character
 folding in the middle of a search by typing 'M-s ''.
 
 'query-replace' honors character folding if the new variable
-'replace-character-fold' is customized to a non-nil value.
+'replace-char-fold' is customized to a non-nil value.
 
 +++
 *** New user option 'search-default-mode'.
@@ -1124,9 +1124,9 @@ value, nil specifies that Isearch does literal searches (however,
 as in previous Emacs versions).
 
 +++
-*** New function 'character-fold-to-regexp' can be used
+*** New function 'char-fold-to-regexp' can be used
 by searching commands to produce a regexp matching anything that
-character-folds into STRING.
+char-folds into STRING.
 
 +++
 *** The new 'M-s M-w' key binding uses eww to search the web for the
diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index 49dada970bb..bc814169b79 100644
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -718,6 +718,20 @@ the following variables: tex-font-script-display (how much to
 lower/raise); tex-suscript-height-ratio (how much smaller than
 normal); tex-suscript-height-minimum (minimum height).
 
+** Screen refresh is slow when there are special characters for which no suitable font is available
+
+If the display is too slow in refreshing when you scroll to a new
+region, or when you edit the buffer, it might be due to the fact that
+some characters cannot be displayed in the default font, and Emacs is
+spending too much time in looking for a suitable font to display them.
+
+You can suspect this if you have several characters that are displayed
+as small rectangles containing a hexadecimal code inside.
+
+The solution is to install the appropriate fonts on your machine. For
+instance if you are editing a text with a lot of math symbols, then
+installing a font like 'Symbola' should solve this problem.
+
 * Internationalization problems
 
 ** M-{ does not work on a Spanish PC keyboard.
@@ -909,6 +923,21 @@ into Meta.  This is because of the great importance of Meta in Emacs.
 
 ** Window-manager and toolkit-related problems
 
+*** Emacs built with GTK+ toolkit produces corrupted display on HiDPI screen
+
+This can happen if you set GDK_SCALE=2 in the environment or in your
+'.xinitrc' file.  (This setting is usually accompanied by
+GDK_DPI_SCALE=0.5.)  Emacs can not support these settings correctly,
+as it doesn't use GTK+ exclusively.  The result is that sometimes
+widgets like the scroll bar are displayed incorrectly, and frames
+could be displayed "cropped" to only part of the stuff that should be
+displayed.
+
+The workaround is to explicitly disable these settings when invoking
+Emacs, for example (from a Posix shell prompt):
+
+  $ GDK_SCALE=1 GDK_DPI_SCALE=1 emacs
+
 *** Metacity: Resizing Emacs or ALT-Tab causes X to be unresponsive.
 
 This happens sometimes when using Metacity.  Resizing Emacs or ALT-Tab:bing
@@ -2561,51 +2590,70 @@ See <URL:http://debbugs.gnu.org/327>, <URL:http://debbugs.gnu.org/821>.
 
 ** Dumping
 
-*** Segfault during 'make bootstrap' under the Linux kernel.
+*** Segfault during 'make'
 
-In Red Hat Linux kernels, "Exec-shield" functionality is enabled by
-default, which creates a different memory layout that can break the
-emacs dumper.  Emacs tries to handle this at build time, but if this
-fails, the following instructions may be useful.
+If Emacs segfaults when 'make' executes one of these commands:
 
-Exec-shield is enabled on your system if
+  LC_ALL=C ./temacs -batch -l loadup bootstrap
+  LC_ALL=C ./temacs -batch -l loadup dump
 
-    cat /proc/sys/kernel/exec-shield
+the problem may be due to inadequate workarounds for address space
+layout randomization (ASLR), an operating system feature that
+randomizes the virtual address space of a process.  ASLR is commonly
+enabled in Linux and NetBSD kernels, and is intended to deter exploits
+of pointer-related bugs in applications.  If ASLR is enabled, the
+command:
 
-prints a value other than 0.  (Please read your system documentation
-for more details on Exec-shield and associated commands.)
+   cat /proc/sys/kernel/randomize_va_space  # GNU/Linux
+   sysctl security.pax.aslr.global          # NetBSD
 
-Additionally, Linux kernel versions since 2.6.12 randomize the virtual
-address space of a process by default.  If this feature is enabled on
-your system, then
+outputs a nonzero value.
 
-   cat /proc/sys/kernel/randomize_va_space
+These segfaults should not occur on most modern systems, because the
+Emacs build procedure uses the command 'setfattr' or 'paxctl' to mark
+the Emacs executable as requiring non-randomized address space, and
+Emacs uses the 'personality' system call to disable address space
+randomization when dumping.  However, older kernels may not support
+'setfattr', 'paxctl', or 'personality', and newer Linux kernels have a
+secure computing mode (seccomp) that can be configured to disable the
+'personality' call.
 
-prints a value other than 0.
+It may be possible to work around the 'personality' problem in a newer
+Linux kernel by configuring seccomp to allow the 'personality' call.
+For example, if you are building Emacs under Docker, you can run the
+Docker container with a security profile that allows 'personality' by
+using Docker's --security-opt option with an appropriate profile; see
+<https://docs.docker.com/engine/security/seccomp/>.
 
-When these features are enabled, building Emacs may segfault during
-the execution of this command:
+To work around the ASLR problem in either an older or a newer kernel,
+you can temporarily disable the feature while building Emacs.  On
+GNU/Linux you can do so using the following command (as root).
 
-    ./temacs --batch --load loadup [dump|bootstrap]
+    echo 0 > /proc/sys/kernel/randomize_va_space
 
-To work around this problem, you can temporarily disable these
-features while building Emacs.  You can do so using the following
-commands (as root).  Remember to re-enable them when you are done,
-by echoing the original values back to the files.
+You can re-enable the feature when you are done, by echoing the
+original value back to the file.  NetBSD uses a different command,
+e.g., 'sysctl -w security.pax.aslr.global=0'.
 
-    echo 0 > /proc/sys/kernel/exec-shield
-    echo 0 > /proc/sys/kernel/randomize_va_space
+Alternatively, you can try using the 'setarch' command when building
+temacs like this, where -R disables address space randomization:
 
-Or, on x86, you can try using the 'setarch' command when running
-temacs, like this:
+    setarch $(uname -m) -R make
 
-    setarch i386 -R ./temacs --batch --load loadup [dump|bootstrap]
+ASLR is not the only problem that can break Emacs dumping.  Another
+issue is that in Red Hat Linux kernels, Exec-shield is enabled by
+default, and this creates a different memory layout.  Emacs should
+handle this at build time, but if this fails the following
+instructions may be useful.  Exec-shield is enabled on your system if
 
-or
+    cat /proc/sys/kernel/exec-shield
+
+prints a nonzero value.  You can temporarily disable it as follows:
 
-    setarch i386 -R make
+    echo 0 > /proc/sys/kernel/exec-shield
 
-(The -R option disables address space randomization.)
+As with randomize_va_space, you can re-enable Exec-shield when you are
+done, by echoing the original value back to the file.
 
 *** temacs prints "Pure Lisp storage exhausted".