Merge from origin/emacs-26

eb903d8 * lisp/emacs-lisp/pcase.el: Improve docstrings.
86abbb3 * lisp/emacs-lisp/rx.el (rx): Fix typo in doc string.  (Bug#3...
ced58d3 Improve doc string of 'call-process'
38f88a7 Document that generic functions cannot be commands
5aeddfa * lisp/mail/rmailsum.el (rmail-summary-output): Add lost word...
10e0fd8 Add index entries for more isearch commands/bindings (Bug#32990)
de28184 * lisp/simple.el (filter-buffer-substring): Clarify doc (Bug#...
d192c16 Fix recent change in lispref/processes.texi.

4 files changed, 15 insertions, 9 deletions

diff --git a/lisp/emacs-lisp/pcase.el b/lisp/emacs-lisp/pcase.el
index 57c2d6c3cb5..2746738d41a 100644
--- a/lisp/emacs-lisp/pcase.el
+++ b/lisp/emacs-lisp/pcase.el
@@ -266,7 +266,8 @@ variable name being but a special case of it)."
 (defmacro pcase-let* (bindings &rest body)
   "Like `let*' but where you can use `pcase' patterns for bindings.
 BODY should be an expression, and BINDINGS should be a list of bindings
-of the form (PAT EXP)."
+of the form (PATTERN EXP).
+See `pcase-let' for discussion of how PATTERN is matched."
   (declare (indent 1)
            (debug ((&rest (pcase-PAT &optional form)) body)))
   (let ((cached (gethash bindings pcase--memoize)))
@@ -281,10 +282,11 @@ of the form (PAT EXP)."
 (defmacro pcase-let (bindings &rest body)
   "Like `let' but where you can use `pcase' patterns for bindings.
 BODY should be a list of expressions, and BINDINGS should be a list of bindings
-of the form (PAT EXP).
-The macro is expanded and optimized under the assumption that those
-patterns *will* match, so a mismatch may go undetected or may cause
-any kind of error."
+of the form (PATTERN EXP).
+The PATTERNs are only used to extract data, so the code does not test
+whether the data does match the corresponding patterns: a mismatch
+may signal an error or may go undetected, binding variables to arbitrary
+values, such as nil."
   (declare (indent 1) (debug pcase-let*))
   (if (null (cdr bindings))
       `(pcase-let* ,bindings ,@body)
@@ -302,7 +304,11 @@ any kind of error."
 
 ;;;###autoload
 (defmacro pcase-dolist (spec &rest body)
-  "Like `dolist' but where the binding can be a `pcase' pattern.
+  "Superset of `dolist' where the VAR binding can be a `pcase' PATTERN.
+More specifically, this is just a shorthand for the following combination
+of `dolist' and `pcase-let':
+
+    (dolist (x LIST) (pcase-let ((PATTERN x)) BODY...))
 \n(fn (PATTERN LIST) BODY...)"
   (declare (indent 1) (debug ((pcase-PAT form) body)))
   (if (pcase--trivial-upat-p (car spec))
diff --git a/lisp/emacs-lisp/rx.el b/lisp/emacs-lisp/rx.el
index bb759011513..1230df4f15d 100644
--- a/lisp/emacs-lisp/rx.el
+++ b/lisp/emacs-lisp/rx.el
@@ -1060,7 +1060,7 @@ CHAR
      `chinese-two-byte'                 (\\cC)
      `greek-two-byte'                   (\\cG)
      `japanese-hiragana-two-byte'       (\\cH)
-     `indian-tow-byte'                  (\\cI)
+     `indian-two-byte'                  (\\cI)
      `japanese-katakana-two-byte'       (\\cK)
      `korean-hangul-two-byte'           (\\cN)
      `cyrillic-two-byte'                (\\cY)
diff --git a/lisp/mail/rmailsum.el b/lisp/mail/rmailsum.el
index 10345b63ae2..f8adf774002 100644
--- a/lisp/mail/rmailsum.el
+++ b/lisp/mail/rmailsum.el
@@ -1694,7 +1694,7 @@ Deleted messages are skipped and don't count.
 When called from Lisp code, N may be omitted and defaults to 1.
 
 This command always outputs the complete message header,
-even the header display is currently pruned."
+even if the header display is currently pruned."
   (interactive
    (progn (require 'rmailout)
           (list (rmail-output-read-file-name)
diff --git a/lisp/simple.el b/lisp/simple.el
index 6a7d210e483..245675504a3 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -4266,7 +4266,7 @@ unless a hook has been set.
 Use `filter-buffer-substring' instead of `buffer-substring',
 `buffer-substring-no-properties', or `delete-and-extract-region' when
 you want to allow filtering to take place.  For example, major or minor
-modes can use `filter-buffer-substring-function' to extract characters
+modes can use `filter-buffer-substring-function' to exclude text properties
 that are special to a buffer, and should not be copied into other buffers."
   (funcall filter-buffer-substring-function beg end delete))