Merge from origin/emacs-26

b94d767 (origin/emacs-26) Minor copyedits in last manual change
73508e6 Improve documentation of face numbers
bf235ce * doc/emacs/custom.texi (Authentication): Refer to the "Help ...
ceccb3c New node Authentication in the Emacs manual
9078f34 Fix a loop in c-fl-decl-start.  This fixes bug #34186.
a177fe7 Fix LaTeX output of month and day from cal-tex.el
90177d7 Avoid elisp crash for OpenPGP User IDs with no e-mail address
68e55a0 image-mode: Do not use default scaling (bug#33990)
b6c762a create-image: Expand documentation (bug#33990)
928d342 Improve documentation of 'isearch-filter-predicate'
9034dd6 Fix cursor column positioning on Grep hits

# Conflicts:
#	doc/emacs/custom.texi

3 files changed, 47 insertions, 0 deletions

diff --git a/doc/emacs/custom.texi b/doc/emacs/custom.texi
index 618692e479f..474149fcae6 100644
--- a/doc/emacs/custom.texi
+++ b/doc/emacs/custom.texi
@@ -32,6 +32,8 @@ Reference Manual}.
                           By changing them, you can redefine keys.
 * Init File::           How to write common customizations in the
                           initialization file.
+* Authentication::      Keeping persistent authentication information.
+
 @end menu
 
 @node Easy Customization
@@ -2639,3 +2641,40 @@ provided by the Emacs startup, such as @code{window-setup-hook} or
 
   For more information on the early init file, @pxref{Init File,,,
 elisp, The Emacs Lisp Reference Manual}.
+
+@node Authentication
+@section Keeping Persistent Authentication Information
+
+  Some Emacs packages, which connect to other services, require
+authentication (@pxref{Passwords}), e.g., see @ref{Top, Gnus,, gnus, The
+Gnus Manual}, or @ref{Top, Tramp,, tramp, The Tramp Manual}.  Because
+it might be annoying to provide the same user name and password again
+and again, Emacs offers to keep this information persistent via the
+@file{auth-source} library.
+
+@cindex @file{~/.authinfo} file
+@cindex @file{~/.authinfo.gpg} file
+@cindex ~/.netrc file
+  By default, the authentication information is taken from the file
+@file{~/.authinfo} or @file{~/.authinfo.gpg} or @file{~/.netrc}.
+These files have a syntax similar to netrc files as known from the
+@command{ftp} program, like this:
+
+@example
+machine @var{mymachine} login @var{myloginname} password @var{mypassword} port @var{myport}
+@end example
+
+  Similarly, the @file{auth-source} library supports multiple storage
+backend, currently either the classic netrc backend, JSON files, the
+Secret Service API, and pass, the standard unix password manager.
+
+@vindex auth-sources
+  All these alternatives can be customized via the user option
+@code{auth-sources}, see @ref{Help for users, Emacs auth-source,,
+auth, Emacs auth-source}.
+
+@vindex auth-source-save-behavior
+  When a password is entered interactively, which is not found via the
+configured backend, some of the backends offer to save it
+persistently.  This can be changed by customizing the user option
+@code{auth-source-save-behavior}.
diff --git a/doc/emacs/emacs.texi b/doc/emacs/emacs.texi
index 54c20251ef7..950ddc01123 100644
--- a/doc/emacs/emacs.texi
+++ b/doc/emacs/emacs.texi
@@ -1114,6 +1114,7 @@ Customization
                           By changing them, you can redefine keys.
 * Init File::           How to write common customizations in the
                           initialization file.
+* Authentication::      Keeping persistent authentication information.
 
 Easy Customization Interface
 
diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index 350b3108715..95379b342b3 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -3079,10 +3079,17 @@ value, which inherits from @var{face}'s global definition.
 This function returns a list of all defined face names.
 @end defun
 
+@cindex face number
+@cindex face property of face symbols
 @defun face-id face
 This function returns the @dfn{face number} of face @var{face}.  This
 is a number that uniquely identifies a face at low levels within
 Emacs.  It is seldom necessary to refer to a face by its face number.
+However, functions that manipulate glyphs, such as
+@code{make-glyph-code} and @code{glyph-face} (@pxref{Glyphs}) access
+the face numbers internally.  Note that the face number is stored as
+the value of the @code{face} property of the face symbol, so we
+recommend not to set that property of a face to any value of your own.
 @end defun
 
 @defun face-documentation face