Merge from origin/emacs-26

0276743 (origin/emacs-26) Doc string fix in latin-alt.el
c9269af Minor improvements in package.texi
898a3e4 Minor improvement in Emacs user manual
8f7d718 * doc/lispref/anti.texi (Antinews): Replace 25.2 with 25.3.
989d0af Improve documentation of mini-window resizing
923e415 More changes in the Emacs manual
565adf2 Clarify that text-quoting-style doesn't affect *Info* (Bug#24...
2dd273b Mention that shell quoting of % on w32 may fail (Bug#19350)
19fa6d5 Fix --no-build-details for w32 and macOS
979944c * doc/lispref/anti.texi (Antinews): Add some more antinews.
c2727e3 Fix crashes when run with --no-build-details
dc08490 More changes for the manual
04c5bd5 Doc fixes for process functions (Bug#30349)
e209034 Fix shr and CSS 4 color maps
5fe8192 Yet another round of improvements in the manual

Conflicts:
	doc/emacs/files.texi
	test/lisp/subr-tests.el

5 files changed, 41 insertions, 29 deletions

diff --git a/src/doc.c b/src/doc.c
index 2b36c786a66..3424bffdf9a 100644
--- a/src/doc.c
+++ b/src/doc.c
@@ -1023,8 +1023,8 @@ syms_of_doc (void)
                doc: /* Style to use for single quotes in help and messages.
 Its value should be a symbol.  It works by substituting certain single
 quotes for grave accent and apostrophe.  This is done in help output
-and in functions like `message' and `format-message'.  It is not done
-in `format'.
+\(but not for display of Info manuals) and in functions like `message'
+and `format-message'.  It is not done in `format'.
 
 `curve' means quote with curved single quotes ‘like this’.
 `straight' means quote with straight apostrophes \\='like this\\='.
diff --git a/src/process.c b/src/process.c
index ff3edbb11a0..2cc2c86df39 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1615,9 +1615,8 @@ to make it unique.
 
 :buffer BUFFER -- BUFFER is the buffer (or buffer-name) to associate
 with the process.  Process output goes at end of that buffer, unless
-you specify an output stream or filter function to handle the output.
-BUFFER may be also nil, meaning that this process is not associated
-with any buffer.
+you specify a filter function to handle the output.  BUFFER may be
+also nil, meaning that this process is not associated with any buffer.
 
 :command COMMAND -- COMMAND is a list starting with the program file
 name, followed by strings to give to the program as arguments.
@@ -2307,8 +2306,8 @@ arguments are defined:
 
 :buffer BUFFER -- BUFFER is the buffer (or buffer-name) to associate
 with the process.  Process output goes at the end of that buffer,
-unless you specify an output stream or filter function to handle the
-output.  If BUFFER is not given, the value of NAME is used.
+unless you specify a filter function to handle the output.  If BUFFER
+is not given, the value of NAME is used.
 
 :coding CODING -- If CODING is a symbol, it specifies the coding
 system used for both reading and writing for this process.  If CODING
@@ -3022,8 +3021,8 @@ the value of PORT is used.
 
 :buffer BUFFER -- BUFFER is the buffer (or buffer-name) to associate
 with the process.  Process output goes at the end of that buffer,
-unless you specify an output stream or filter function to handle the
-output.  If BUFFER is not given, the value of NAME is used.
+unless you specify a filter function to handle the output.  If BUFFER
+is not given, the value of NAME is used.
 
 :coding CODING -- If CODING is a symbol, it specifies the coding
 system used for both reading and writing for this process.  If CODING
@@ -3685,9 +3684,8 @@ to make it unique.
 
 :buffer BUFFER -- BUFFER is the buffer (or buffer-name) to associate
 with the process.  Process output goes at end of that buffer, unless
-you specify an output stream or filter function to handle the output.
-BUFFER may be also nil, meaning that this process is not associated
-with any buffer.
+you specify a filter function to handle the output.  BUFFER may be
+also nil, meaning that this process is not associated with any buffer.
 
 :host HOST -- HOST is name of the host to connect to, or its IP
 address.  The symbol `local' specifies the local host.  If specified
diff --git a/src/w32term.c b/src/w32term.c
index 137c798c463..c1d039c1375 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -6922,10 +6922,15 @@ w32_initialize_display_info (Lisp_Object display_name)
   memset (dpyinfo, 0, sizeof (*dpyinfo));
 
   dpyinfo->name_list_element = Fcons (display_name, Qnil);
-  dpyinfo->w32_id_name = xmalloc (SCHARS (Vinvocation_name)
-                                  + SCHARS (Vsystem_name) + 2);
-  sprintf (dpyinfo->w32_id_name, "%s@%s",
-           SDATA (Vinvocation_name), SDATA (Vsystem_name));
+  if (STRINGP (Vsystem_name))
+    {
+      dpyinfo->w32_id_name = xmalloc (SCHARS (Vinvocation_name)
+                                      + SCHARS (Vsystem_name) + 2);
+      sprintf (dpyinfo->w32_id_name, "%s@%s",
+               SDATA (Vinvocation_name), SDATA (Vsystem_name));
+    }
+  else
+    dpyinfo->w32_id_name = xlispstrdup (Vinvocation_name);
 
   /* Default Console mode values - overridden when running in GUI mode
      with values obtained from system metrics.  */
diff --git a/src/xrdb.c b/src/xrdb.c
index b55c0f9011e..836c147947a 100644
--- a/src/xrdb.c
+++ b/src/xrdb.c
@@ -376,15 +376,18 @@ get_environ_db (void)
 
   if (!p)
     {
-      /* Use ~/.Xdefaults-HOSTNAME.  */
-      char *home = gethomedir ();
-      ptrdiff_t homelen = strlen (home);
       Lisp_Object system_name = Fsystem_name ();
-      ptrdiff_t filenamesize = (homelen + sizeof xdefaults
-                                + 1 + SBYTES (system_name));
-      p = filename = xrealloc (home, filenamesize);
-      lispstpcpy (stpcpy (stpcpy (filename + homelen, xdefaults), "-"),
-                  system_name);
+      if (STRINGP (system_name))
+        {
+          /* Use ~/.Xdefaults-HOSTNAME.  */
+          char *home = gethomedir ();
+          ptrdiff_t homelen = strlen (home);
+          ptrdiff_t filenamesize = (homelen + sizeof xdefaults
+                                    + 1 + SBYTES (system_name));
+          p = filename = xrealloc (home, filenamesize);
+          lispstpcpy (stpcpy (stpcpy (filename + homelen, xdefaults), "-"),
+                      system_name);
+        }
     }
 
   db = XrmGetFileDatabase (p);
diff --git a/src/xterm.c b/src/xterm.c
index 7603e4f3991..deae65d1d8a 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -12141,6 +12141,8 @@ same_x_server (const char *name1, const char *name2)
 {
   bool seen_colon = false;
   Lisp_Object sysname = Fsystem_name ();
+  if (! STRINGP (sysname))
+    sysname = empty_unibyte_string;
   const char *system_name = SSDATA (sysname);
   ptrdiff_t system_name_length = SBYTES (sysname);
   ptrdiff_t length_until_period = 0;
@@ -12563,15 +12565,19 @@ x_term_init (Lisp_Object display_name, char *xrm_option, char *resource_name)
 #endif
 
   Lisp_Object system_name = Fsystem_name ();
-  ptrdiff_t nbytes;
-  if (INT_ADD_WRAPV (SBYTES (Vinvocation_name), SBYTES (system_name) + 2,
-                     &nbytes))
+
+  ptrdiff_t nbytes = SBYTES (Vinvocation_name) + 1;
+  if (STRINGP (system_name)
+      && INT_ADD_WRAPV (nbytes, SBYTES (system_name) + 1, &nbytes))
     memory_full (SIZE_MAX);
   dpyinfo->x_id = ++x_display_id;
   dpyinfo->x_id_name = xmalloc (nbytes);
   char *nametail = lispstpcpy (dpyinfo->x_id_name, Vinvocation_name);
-  *nametail++ = '@';
-  lispstpcpy (nametail, system_name);
+  if (STRINGP (system_name))
+    {
+      *nametail++ = '@';
+      lispstpcpy (nametail, system_name);
+    }
 
   /* Figure out which modifier bits mean what.  */
   x_find_modifier_meanings (dpyinfo);