Fix more regular expression typos

Problem reported by Mattias Engdegård in:
https://lists.gnu.org/r/emacs-devel/2019-03/msg00548.html
except that I didn’t address the issues involving Hebrew,
or involving comint-prompt-regexp.
* lisp/align.el (align-rules-list, align-exclude-rules-list):
* lisp/auth-source-pass.el (auth-source-pass--parse-secret)
(auth-source-pass--parse-data):
* lisp/cedet/data-debug.el (data-debug-next)
(data-debug-prev, data-debug-expand-or-contract):
* lisp/comint.el (comint-within-quotes):
* lisp/emacs-lisp/checkdoc.el (checkdoc-this-string-valid-engine):
* lisp/emulation/viper-ex.el (ex-cmd-complete):
* lisp/gnus/gnus-cite.el (gnus-message-search-citation-line):
* lisp/gnus/nnir.el (nnir-imap-end-of-input):
* lisp/mail/mail-extr.el (mail-extr-all-letters):
* lisp/minibuffer.el (minibuffer-maybe-quote-filename):
* lisp/nxml/rng-nxml.el (rng-complete-tag)
(rng-complete-end-tag, rng-complete-attribute-name):
* lisp/obsolete/vip.el (vip-get-ex-token, vip-get-ex-pat):
* lisp/org/org-pcomplete.el (org-thing-at-point):
* lisp/org/org.el (org-set-tags)
(org-increase-number-at-point)
(org-fill-line-break-nobreak-p):
* lisp/pcomplete.el (pcomplete-parse-comint-arguments):
* lisp/progmodes/ada-mode.el (ada-compile-goto-error):
* lisp/progmodes/cperl-mode.el (cperl-highlight-charclass)
(cperl-find-pods-heres, cperl-not-bad-style-regexp)
(cperl-regext-to-level-start):
* lisp/progmodes/ebnf-yac.el (ebnf-yac-skip-spaces):
* lisp/progmodes/flymake-proc.el (flymake-proc-master-tex-init):
* lisp/progmodes/flymake.el (flymake-diag-region):
* lisp/progmodes/fortran.el (fortran-current-line-indentation):
* lisp/progmodes/idlw-complete-structtag.el:
(idlwave-complete-structure-tag):
* lisp/progmodes/idlwave.el (idlwave-complete-sysvar-or-tag):
* lisp/progmodes/prolog.el (prolog-pred-end)
(prolog-clause-info):
* lisp/progmodes/ruby-mode.el (ruby-forward-sexp)
(ruby-backward-sexp):
* lisp/progmodes/verilog-mode.el (verilog-repair-open-comma):
* lisp/term.el (term-within-quotes):
* lisp/textmodes/bib-mode.el (bib-capitalize-title-stop-words):
* lisp/textmodes/refbib.el (r2b-capitalize-title-stop-words):
* lisp/textmodes/reftex-parse.el (reftex-nth-arg):
* lisp/textmodes/rst.el (rst-svn-rev):
* lisp/url/url-http.el (url-http-parse-response):
* test/lisp/progmodes/f90-tests.el (f90-test-bug3730):
Fix regular expression typos.

33 files changed, 56 insertions, 64 deletions

diff --git a/lisp/align.el b/lisp/align.el
index 594d15eee15..a81498be5d0 100644
--- a/lisp/align.el
+++ b/lisp/align.el
@@ -452,7 +452,7 @@ The possible settings for `align-region-separate' are:
      (tab-stop . nil))
 
     (make-assignment
-     (regexp   . "^\\s-*\\w+\\(\\s-*\\):?=\\(\\s-*\\)\\([^\t\n \\\\]\\|$\\)")
+     (regexp   . "^\\s-*\\w+\\(\\s-*\\):?=\\(\\s-*\\)\\([^\t\n \\]\\|$\\)")
      (group    . (1 2))
      (modes    . '(makefile-mode))
      (tab-stop . nil))
@@ -759,7 +759,7 @@ The following attributes are meaningful:
 	  (lambda (end reverse)
 	    (funcall (if reverse 're-search-backward
 		       're-search-forward)
-		     (concat "[^ \t\n\\\\]"
+		     (concat "[^ \t\n\\]"
 			     (regexp-quote comment-start)
 			     "\\(.+\\)$") end t))))
      (modes  . align-open-comment-modes))
diff --git a/lisp/auth-source-pass.el b/lisp/auth-source-pass.el
index deb805a6e1a..29ff9c66856 100644
--- a/lisp/auth-source-pass.el
+++ b/lisp/auth-source-pass.el
@@ -134,12 +134,12 @@ ENTRY is the name of a password-store entry."
 (defun auth-source-pass--parse-secret (contents)
   "Parse the password-store data in the string CONTENTS and return its secret.
 The secret is the first line of CONTENTS."
-  (car (split-string contents "\\\n" t)))
+  (car (split-string contents "\n" t)))
 
 (defun auth-source-pass--parse-data (contents)
   "Parse the password-store data in the string CONTENTS and return an alist.
 CONTENTS is the contents of a password-store formatted file."
-  (let ((lines (split-string contents "\\\n" t "\\\s")))
+  (let ((lines (split-string contents "\n" t "\\\s")))
     (seq-remove #'null
                 (mapcar (lambda (line)
                           (let ((pair (mapcar (lambda (s) (string-trim s))
diff --git a/lisp/cedet/data-debug.el b/lisp/cedet/data-debug.el
index ba312433d38..eeec6b5834b 100644
--- a/lisp/cedet/data-debug.el
+++ b/lisp/cedet/data-debug.el
@@ -920,14 +920,14 @@ If PARENT is non-nil, it is somehow related as a parent to thing."
   (interactive)
   (forward-line 1)
   (beginning-of-line)
-  (skip-chars-forward " *-><[]" (point-at-eol)))
+  (skip-chars-forward "- *><[]" (point-at-eol)))
 
 (defun data-debug-prev ()
   "Go to the previous line in the Ddebug buffer."
   (interactive)
   (forward-line -1)
   (beginning-of-line)
-  (skip-chars-forward " *-><[]" (point-at-eol)))
+  (skip-chars-forward "- *><[]" (point-at-eol)))
 
 (defun data-debug-next-expando ()
   "Go to the next line in the Ddebug buffer.
@@ -1014,7 +1014,7 @@ Do nothing if already contracted."
 	   (data-debug-current-line-expanded-p))
       (data-debug-contract-current-line)
     (data-debug-expand-current-line))
-  (skip-chars-forward " *-><[]" (point-at-eol)))
+  (skip-chars-forward "- *><[]" (point-at-eol)))
 
 (defun data-debug-expand-or-contract-mouse (event)
   "Expand or contract anything at event EVENT."
diff --git a/lisp/comint.el b/lisp/comint.el
index a5fca7ea2a1..a71821baa5e 100644
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -1618,8 +1618,8 @@ Go to the history element by the absolute history position HIST-POS."
 (defun comint-within-quotes (beg end)
   "Return t if the number of quotes between BEG and END is odd.
 Quotes are single and double."
-  (let ((countsq (comint-how-many-region "\\(^\\|[^\\\\]\\)'" beg end))
-	(countdq (comint-how-many-region "\\(^\\|[^\\\\]\\)\"" beg end)))
+  (let ((countsq (comint-how-many-region "\\(^\\|[^\\]\\)'" beg end))
+	(countdq (comint-how-many-region "\\(^\\|[^\\]\\)\"" beg end)))
     (or (= (mod countsq 2) 1) (= (mod countdq 2) 1))))
 
 (defun comint-how-many-region (regexp beg end)
diff --git a/lisp/emacs-lisp/checkdoc.el b/lisp/emacs-lisp/checkdoc.el
index dca2f169567..fa6f85c588d 100644
--- a/lisp/emacs-lisp/checkdoc.el
+++ b/lisp/emacs-lisp/checkdoc.el
@@ -1511,7 +1511,7 @@ may require more formatting")
 					      (line-end-position))))))))
      ;; Continuation of above.  Make sure our sentence is capitalized.
      (save-excursion
-       (skip-chars-forward "\"\\*")
+       (skip-chars-forward "\"*")
        (if (looking-at "[a-z]")
 	   (if (checkdoc-autofix-ask-replace
 		(match-beginning 0) (match-end 0)
diff --git a/lisp/emulation/viper-ex.el b/lisp/emulation/viper-ex.el
index f5090573c86..45b91cd9c0e 100644
--- a/lisp/emulation/viper-ex.el
+++ b/lisp/emulation/viper-ex.el
@@ -565,7 +565,7 @@ reversed."
   (let (save-pos dist compl-list string-to-complete completion-result)
 
     (save-excursion
-      (setq dist (skip-chars-backward "[a-zA-Z!=>&~]")
+      (setq dist (skip-chars-backward "a-zA-Z!=>&~")
 	    save-pos (point)))
 
     (if (or (= dist 0)
diff --git a/lisp/gnus/gnus-cite.el b/lisp/gnus/gnus-cite.el
index 2216d4a0420..7e431e79fc7 100644
--- a/lisp/gnus/gnus-cite.el
+++ b/lisp/gnus/gnus-cite.el
@@ -1128,7 +1128,7 @@ Returns nil if there is no such line before LIMIT, t otherwise."
     (let ((cdepth (min (length (apply 'concat
 				      (split-string
 				       (match-string-no-properties 0)
-				       "[ \t [:alnum:]]+")))
+				       "[\t [:alnum:]]+")))
 		       gnus-message-max-citation-depth))
 	  (mlist (make-list (* (1+ gnus-message-max-citation-depth) 2) nil))
 	  (start (point-at-bol))
diff --git a/lisp/gnus/nnir.el b/lisp/gnus/nnir.el
index 7c94abde0d7..37a38a58d46 100644
--- a/lisp/gnus/nnir.el
+++ b/lisp/gnus/nnir.el
@@ -1185,7 +1185,7 @@ returning the one at the supplied position."
 
 (defun nnir-imap-end-of-input ()
   "Are we at the end of input?"
-  (skip-chars-forward "[[:blank:]]")
+  (skip-chars-forward "[:blank:]")
   (looking-at "$"))
 
 
diff --git a/lisp/mail/mail-extr.el b/lisp/mail/mail-extr.el
index ae849d7b62b..cb57d8ea016 100644
--- a/lisp/mail/mail-extr.el
+++ b/lisp/mail/mail-extr.el
@@ -293,7 +293,7 @@ by translating things like \"foo!bar!baz@host\" into \"baz@bar.UUCP\"."
 ;; multipart names.
 ;; #### should . be in here?
 (defconst mail-extr-all-letters
-  (purecopy (concat mail-extr-all-letters-but-separators "---")))
+  (purecopy (concat mail-extr-all-letters-but-separators "-")))
 
 ;; Any character that can start a name.
 ;; Keep this set as minimal as possible.
@@ -305,19 +305,11 @@ by translating things like \"foo!bar!baz@host\" into \"baz@bar.UUCP\"."
 
 (defconst mail-extr-leading-garbage "\\W+")
 
-;; (defconst mail-extr-non-name-chars
-;;   (purecopy (concat "^" mail-extr-all-letters ".")))
 ;; (defconst mail-extr-non-begin-name-chars
 ;;   (purecopy (concat "^" mail-extr-first-letters)))
 ;; (defconst mail-extr-non-end-name-chars
 ;;   (purecopy (concat "^" mail-extr-last-letters)))
 
-;; Matches an initial not followed by both a period and a space.
-;; (defconst mail-extr-bad-initials-pattern
-;;   (purecopy
-;;    (format "\\(\\([^%s]\\|\\`\\)[%s]\\)\\(\\.\\([^ ]\\)\\| \\|\\([^%s .]\\)\\|\\'\\)"
-;;            mail-extr-all-letters mail-extr-first-letters mail-extr-all-letters)))
-
 ;; Matches periods used instead of spaces.  Must not match the period
 ;; following an initial.
 (defconst mail-extr-bad-dot-pattern
diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index c5d714846d7..df0acbb343d 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -2297,7 +2297,7 @@ Useful to give the user default values that won't be substituted."
   (if (and (not (file-name-quoted-p filename))
            (file-name-absolute-p filename)
            (string-match-p (if (memq system-type '(windows-nt ms-dos))
-                               "[/\\\\]~" "/~")
+                               "[/\\]~" "/~")
                            (file-local-name filename)))
       (file-name-quote filename)
     (minibuffer--double-dollars filename)))
diff --git a/lisp/nxml/rng-nxml.el b/lisp/nxml/rng-nxml.el
index c110937b34b..05b59316d13 100644
--- a/lisp/nxml/rng-nxml.el
+++ b/lisp/nxml/rng-nxml.el
@@ -160,7 +160,7 @@ Validation will be enabled if `rng-nxml-auto-validate-flag' is non-nil."
       (and rng-collecting-text (rng-flush-text))
       (let ((target-names (rng-match-possible-start-tag-names)))
         `(,(1+ lt-pos)
-          ,(save-excursion (skip-chars-forward "[[:alnum:]_.-:]") (point))
+          ,(save-excursion (skip-chars-forward "-[:alnum:]_.:") (point))
           ,(apply-partially #'rng-complete-qname-function
                             target-names nil extra-strings)
           :exit-function
@@ -207,7 +207,7 @@ Validation will be enabled if `rng-nxml-auto-validate-flag' is non-nil."
 			      (cdar rng-open-elements))
 		    (cdar rng-open-elements))))
              `(,(+ (match-beginning 0) 2)
-               ,(save-excursion (skip-chars-forward "[[:alnum:]_.-:]") (point))
+               ,(save-excursion (skip-chars-forward "-[:alnum:]_.:") (point))
                ,(list start-tag-name)   ;Sole completion candidate.
                :exit-function
                ,(lambda (_completion status)
@@ -247,7 +247,7 @@ Validation will be enabled if `rng-nxml-auto-validate-flag' is non-nil."
 			      "xmlns"))
 			  rng-undeclared-prefixes)))
              `(,attribute-start
-               ,(save-excursion (skip-chars-forward "[[:alnum:]_.-:]") (point))
+               ,(save-excursion (skip-chars-forward "-[:alnum:]_.:") (point))
                ,(apply-partially #'rng-complete-qname-function
                                  target-names t extra-strings)
                :exit-function
diff --git a/lisp/obsolete/vip.el b/lisp/obsolete/vip.el
index 0360db9bca0..bc4b90031ea 100644
--- a/lisp/obsolete/vip.el
+++ b/lisp/obsolete/vip.el
@@ -2216,7 +2216,7 @@ a token has type \(command, address, end-mark\) and value."
 	     (while (and (not (eolp)) cont)
 	       ;;(re-search-forward "[^/]*/")
 	       (re-search-forward "[^/]*\\(/\\|\n\\)")
-	       (if (not (vip-looking-back "[^\\\\]\\(\\\\\\\\\\)*\\\\/"))
+	       (if (not (vip-looking-back "[^\\]\\(\\\\\\\\\\)*\\\\/"))
 		   (setq cont nil))))
 	   (backward-char 1)
 	   (setq ex-token (buffer-substring (point) (mark)))
@@ -2229,7 +2229,7 @@ a token has type \(command, address, end-mark\) and value."
 	     (while (and (not (eolp)) cont)
 	       ;;(re-search-forward "[^\\?]*\\?")
 	       (re-search-forward "[^\\?]*\\(\\?\\|\n\\)")
-	       (if (not (vip-looking-back "[^\\\\]\\(\\\\\\\\\\)*\\\\\\?"))
+	       (if (not (vip-looking-back "[^\\]\\(\\\\\\\\\\)*\\\\\\?"))
 		   (setq cont nil))
 	       (backward-char 1)
 	       (if (not (looking-at "\n")) (forward-char 1))))
@@ -2325,7 +2325,7 @@ a token has type \(command, address, end-mark\) and value."
 	    (while (and (not (eolp)) cont)
 	      (re-search-forward "[^/]*\\(/\\|\n\\)")
 	      ;;(re-search-forward "[^/]*/")
-	      (if (not (vip-looking-back "[^\\\\]\\(\\\\\\\\\\)*\\\\/"))
+	      (if (not (vip-looking-back "[^\\]\\(\\\\\\\\\\)*\\\\/"))
 		  (setq cont nil))))
 	  (setq ex-token
 		(if (= (mark) (point)) ""
diff --git a/lisp/org/org-pcomplete.el b/lisp/org/org-pcomplete.el
index b8a2f687598..49983c40a52 100644
--- a/lisp/org/org-pcomplete.el
+++ b/lisp/org/org-pcomplete.el
@@ -82,7 +82,7 @@ The return value is a string naming the thing at point."
 	   (not (equal (char-after (point-at-bol)) ?*))
 	   (save-excursion
 	     (move-beginning-of-line 1)
-	     (skip-chars-backward "[ \t\n]")
+	     (skip-chars-backward " \t\n")
 	     ;; org-drawer-regexp matches a whole line but while
 	     ;; looking-back, we just ignore trailing whitespaces
 	     (or (looking-back (substring org-drawer-regexp 0 -1)
diff --git a/lisp/org/org.el b/lisp/org/org.el
index e3c78ae90d4..bf7e305b7a0 100644
--- a/lisp/org/org.el
+++ b/lisp/org/org.el
@@ -14953,7 +14953,7 @@ When JUST-ALIGN is non-nil, only align tags."
 	  (unless (equal tags "")
 	    (let* ((level (save-excursion
 			    (beginning-of-line)
-			    (skip-chars-forward "\\*")))
+			    (skip-chars-forward "*")))
 		   (offset (if (bound-and-true-p org-indent-mode)
 			       (* (1- org-indent-indentation-per-level)
 				  (1- level))
@@ -20615,7 +20615,7 @@ this numeric value."
     (unless inc (setq inc 1))
     (let ((pos (point))
 	  (beg (skip-chars-backward "-+^/*0-9eE."))
-	  (end (skip-chars-forward "-+^/*0-9eE^.")) nap)
+	  (end (skip-chars-forward "-+^/*0-9eE.")) nap)
       (setq nap (buffer-substring-no-properties
 		 (+ pos beg) (+ pos beg end)))
       (delete-region (+ pos beg) (+ pos beg end))
@@ -22837,7 +22837,7 @@ assumed to be significant there."
 (defun org-fill-line-break-nobreak-p ()
   "Non-nil when a new line at point would create an Org line break."
   (save-excursion
-    (skip-chars-backward "[ \t]")
+    (skip-chars-backward " \t")
     (skip-chars-backward "\\\\")
     (looking-at "\\\\\\\\\\($\\|[^\\]\\)")))
 
diff --git a/lisp/pcomplete.el b/lisp/pcomplete.el
index d4ee2c38fa8..ef285db57e8 100644
--- a/lisp/pcomplete.el
+++ b/lisp/pcomplete.el
@@ -768,7 +768,7 @@ this is `comint-dynamic-complete-functions'."
 	(push (point) begins)
         (while
             (progn
-              (skip-chars-forward "^ \t\n\\")
+              (skip-chars-forward "^ \t\n")
               (when (eq (char-after) ?\\)
                 (forward-char 1)
                 (unless (eolp)
diff --git a/lisp/progmodes/ada-mode.el b/lisp/progmodes/ada-mode.el
index 59dc1d0fda6..e01f1e8ecbe 100644
--- a/lisp/progmodes/ada-mode.el
+++ b/lisp/progmodes/ada-mode.el
@@ -767,7 +767,7 @@ the 4 file locations can be clicked on and jumped to."
   (interactive "d")
   (goto-char pos)
 
-  (skip-chars-backward "-a-zA-Z0-9_:./\\")
+  (skip-chars-backward "-a-zA-Z0-9_:./\\\\")
   (cond
    ;;  special case: looking at a filename:line not at the beginning of a line
    ;;  or a simple line reference "at line ..."
diff --git a/lisp/progmodes/cperl-mode.el b/lisp/progmodes/cperl-mode.el
index 970c5669c6c..0b6008a5114 100644
--- a/lisp/progmodes/cperl-mode.el
+++ b/lisp/progmodes/cperl-mode.el
@@ -3507,18 +3507,18 @@ Should be called with the point before leading colon of an attribute."
 (defsubst cperl-highlight-charclass (endbracket dashface bsface onec-space)
   (let ((l '(1 5 7)) ll lle lll
 	;; 2 groups, the first takes the whole match (include \[trnfabe])
-	(singleChar (concat "\\(" "[^\\\\]" "\\|" "\\\\[^cdg-mo-qsu-zA-Z0-9_]" "\\|" "\\\\c." "\\|" "\\\\x" "\\([0-9a-fA-F][0-9a-fA-F]?\\|\\={[0-9a-fA-F]+}\\)" "\\|" "\\\\0?[0-7][0-7]?[0-7]?" "\\|" "\\\\N{[^{}]*}" "\\)")))
+	(singleChar (concat "\\(" "[^\\]" "\\|" "\\\\[^cdg-mo-qsu-zA-Z0-9_]" "\\|" "\\\\c." "\\|" "\\\\x" "\\([0-9a-fA-F][0-9a-fA-F]?\\|\\={[0-9a-fA-F]+}\\)" "\\|" "\\\\0?[0-7][0-7]?[0-7]?" "\\|" "\\\\N{[^{}]*}" "\\)")))
     (while				; look for unescaped - between non-classes
 	(re-search-forward
 	 ;; On 19.33, certain simplifications lead
 	 ;; to bugs (as in  [^a-z] \\| [trnfabe]  )
 	 (concat	       		; 1: SingleChar (include \[trnfabe])
 	  singleChar
-	  ;;"\\(" "[^\\\\]" "\\|" "\\\\[^cdg-mo-qsu-zA-Z0-9_]" "\\|" "\\\\c." "\\|" "\\\\x" "\\([0-9a-fA-F][0-9a-fA-F]?\\|\\={[0-9a-fA-F]+}\\)" "\\|" "\\\\0?[0-7][0-7]?[0-7]?" "\\|" "\\\\N{[^{}]*}" "\\)"
+	  ;;"\\(" "[^\\]" "\\|" "\\\\[^cdg-mo-qsu-zA-Z0-9_]" "\\|" "\\\\c." "\\|" "\\\\x" "\\([0-9a-fA-F][0-9a-fA-F]?\\|\\={[0-9a-fA-F]+}\\)" "\\|" "\\\\0?[0-7][0-7]?[0-7]?" "\\|" "\\\\N{[^{}]*}" "\\)"
 	  "\\("				; 3: DASH SingleChar (match optionally)
 	    "\\(-\\)"			; 4: DASH
 	    singleChar			; 5: SingleChar
-	    ;;"\\(" "[^\\\\]" "\\|" "\\\\[^cdg-mo-qsu-zA-Z0-9_]" "\\|" "\\\\c." "\\|" "\\\\x" "\\([0-9a-fA-F][0-9a-fA-F]?\\|\\={[0-9a-fA-F]+}\\)" "\\|" "\\\\0?[0-7][0-7]?[0-7]?" "\\|" "\\\\N{[^{}]*}" "\\)"
+	    ;;"\\(" "[^\\]" "\\|" "\\\\[^cdg-mo-qsu-zA-Z0-9_]" "\\|" "\\\\c." "\\|" "\\\\x" "\\([0-9a-fA-F][0-9a-fA-F]?\\|\\={[0-9a-fA-F]+}\\)" "\\|" "\\\\0?[0-7][0-7]?[0-7]?" "\\|" "\\\\N{[^{}]*}" "\\)"
 	  "\\)?"
 	  "\\|"
 	  "\\("				; 7: other escapes
@@ -4455,13 +4455,13 @@ the sections using `cperl-pod-head-face', `cperl-pod-face',
 			      ;; Apparently, I can't put \] into a charclass
 			      ;; in m]]: m][\\\]\]] produces [\\]]
 ;;;   POSIX?  [:word:] [:^word:] only inside []
-;;;	       "\\=\\(\\\\.\\|[^][\\\\]\\|\\[:\\^?\sw+:]\\|\\[[^:]\\)*]")
+;;;	       "\\=\\(\\\\.\\|[^][\\]\\|\\[:\\^?\sw+:]\\|\\[[^:]\\)*]")
 			      (while	; look for unescaped ]
 				  (and argument
 				       (re-search-forward
 					(if (eq (char-after b) ?\] )
-					    "\\=\\(\\\\[^]]\\|[^]\\\\]\\)*\\\\]"
-					  "\\=\\(\\\\.\\|[^]\\\\]\\)*]")
+					    "\\=\\(\\\\[^]]\\|[^]\\]\\)*\\\\]"
+					  "\\=\\(\\\\.\\|[^]\\]\\)*]")
 					(1- e) 'toend))
 				;; Is this ] an end of POSIX class?
 				(if (save-excursion
@@ -4580,7 +4580,7 @@ the sections using `cperl-pod-head-face', `cperl-pod-face',
 			      ;; Works also if the outside delimiters are ().
 			      (or;;(if (eq (char-after b) ?\) )
 			       ;;(re-search-forward
-			       ;; "[^\\\\]\\(\\\\\\\\\\)*\\\\)"
+			       ;; "[^\\]\\(\\\\\\\\\\)*\\\\)"
 			       ;; (1- e) 'toend)
 			       (search-forward ")" (1- e) 'toend)
 			       ;;)
@@ -7261,7 +7261,7 @@ One may build such TAGS files from CPerl mode menu."
      ".->"				; a->b
      "->"				; a SPACE ->b
      "\\[-"				; a[-1]
-     "\\\\[&$@*\\\\]"			; \&func
+     "\\\\[&$@*\\]"			; \&func
      "^="				; =head
      "\\$."				; $|
      "<<[a-zA-Z_'\"`]"			; <<FOO, <<'FOO'
@@ -8174,7 +8174,7 @@ We suppose that the regexp is scanned already."
 	  (error "Cannot find `(' which starts a group"))
       (setq done
 	    (save-excursion
-	      (skip-chars-backward "\\")
+	      (skip-chars-backward "\\\\")
 	      (looking-at "\\(\\\\\\\\\\)*(")))
       (or done (forward-char -1)))))
 
diff --git a/lisp/progmodes/ebnf-yac.el b/lisp/progmodes/ebnf-yac.el
index 3365f647c78..9e712353e99 100644
--- a/lisp/progmodes/ebnf-yac.el
+++ b/lisp/progmodes/ebnf-yac.el
@@ -392,7 +392,7 @@ See documentation for variable `ebnf-yac-lex'."
 (defun ebnf-yac-skip-spaces ()
   (skip-chars-forward
    (if ebnf-yac-skip-char
-       "\n\r\t !#$&()*+-.0123456789=?@[\\\\]^_`~"
+       "-\n\r\t !#$&()*+,.0123456789=?@[\\\\]^_`~"
      "\n\r\t ")
    ebnf-limit)
   (< (point) ebnf-limit))
diff --git a/lisp/progmodes/flymake-proc.el b/lisp/progmodes/flymake-proc.el
index 2d9dd047a39..dbf7561944e 100644
--- a/lisp/progmodes/flymake-proc.el
+++ b/lisp/progmodes/flymake-proc.el
@@ -1133,7 +1133,7 @@ Use CREATE-TEMP-F for creating temp copy."
   (let* ((temp-master-file-name (flymake-proc--init-create-temp-source-and-master-buffer-copy
                                  'flymake-proc-get-include-dirs-dot 'flymake-proc-create-temp-inplace
 				 '("\\.tex\\'")
-				 "[ \t]*\\in\\(?:put\\|clude\\)[ \t]*{\\(.*%s\\)}")))
+				 "[ \t]*in\\(?:put\\|clude\\)[ \t]*{\\(.*%s\\)}")))
     (when temp-master-file-name
       (flymake-proc--get-tex-args temp-master-file-name))))
 
diff --git a/lisp/progmodes/flymake.el b/lisp/progmodes/flymake.el
index 830d7009633..d6cd370dac4 100644
--- a/lisp/progmodes/flymake.el
+++ b/lisp/progmodes/flymake.el
@@ -420,7 +420,7 @@ region is invalid."
                        (beg)
                        (progn
                          (end-of-line)
-                         (skip-chars-backward " \t\f\t\n" beg)
+                         (skip-chars-backward " \t\f\n" beg)
                          (if (eq (point) beg)
                              (line-beginning-position 2)
                            (point)))))
diff --git a/lisp/progmodes/fortran.el b/lisp/progmodes/fortran.el
index b8aa521cf66..152667040fa 100644
--- a/lisp/progmodes/fortran.el
+++ b/lisp/progmodes/fortran.el
@@ -1795,7 +1795,7 @@ non-indentation text within the comment."
            (goto-char (match-end 0)))
           (t
            ;; Move past line number.
-           (skip-chars-forward "[ \t0-9]")))
+           (skip-chars-forward " \t0-9")))
     ;; Move past whitespace.
     (skip-chars-forward " \t")
     (current-column)))
diff --git a/lisp/progmodes/idlw-complete-structtag.el b/lisp/progmodes/idlw-complete-structtag.el
index 8a50b9b5375..51c9117cd41 100644
--- a/lisp/progmodes/idlw-complete-structtag.el
+++ b/lisp/progmodes/idlw-complete-structtag.el
@@ -128,7 +128,7 @@ an up-to-date completion list."
           ;; x[i+4].name.g*.  But it is complicated because we would have
           ;; to really parse this expression.  For now, we allow only
           ;; substructures, like "aaa.bbb.ccc.ddd"
-	  (skip-chars-backward "[a-zA-Z0-9._$]")
+	  (skip-chars-backward "a-zA-Z0-9._$")
           (setq start (point)) ;; remember the start of the completion pos.
 	  (and (< (point) pos)
 	       (not (equal (char-before) ?!)) ; no sysvars
diff --git a/lisp/progmodes/idlwave.el b/lisp/progmodes/idlwave.el
index 5ff22571b90..bded09d5038 100644
--- a/lisp/progmodes/idlwave.el
+++ b/lisp/progmodes/idlwave.el
@@ -7590,7 +7590,7 @@ property indicating the link is added."
 	(case-fold-search t))
     (cond ((save-excursion
 	     ;; Check if the context is right for system variable
-	     (skip-chars-backward "[a-zA-Z0-9_$]")
+	     (skip-chars-backward "a-zA-Z0-9_$")
 	     (equal (char-before) ?!))
 	   (setq idlwave-completion-help-info '(idlwave-complete-sysvar-help))
 	   (idlwave-complete-in-buffer 'sysvar 'sysvar
diff --git a/lisp/progmodes/prolog.el b/lisp/progmodes/prolog.el
index 0bc365fcf0f..296a7ac3c95 100644
--- a/lisp/progmodes/prolog.el
+++ b/lisp/progmodes/prolog.el
@@ -2826,7 +2826,7 @@ STRING should be given if the last search was by `string-match' on STRING."
           (progn
             (if (and (eq prolog-system 'mercury)
                      (looking-at
-                      (format ":-[ \t]*\\(pred\\|mode\\)[ \t]+\\(%s+\\)"
+                      (format ":-[ \t]*\\(pred\\|mode\\)[ \t]+\\(\\(?:%s\\)+\\)"
                               prolog-atom-regexp)))
                 ;; Skip predicate declarations
                 (progn
@@ -2950,7 +2950,7 @@ objects (relevant only if `prolog-system' is set to `sicstus')."
            (predname
             (if (looking-at prolog-atom-char-regexp)
                 (progn
-                  (skip-chars-forward "^ (\\.")
+                  (skip-chars-forward "^ (.")
                   (buffer-substring op (point)))
               ""))
            (arity 0))
diff --git a/lisp/progmodes/ruby-mode.el b/lisp/progmodes/ruby-mode.el
index 5998ac8e395..4fceda89373 100644
--- a/lisp/progmodes/ruby-mode.el
+++ b/lisp/progmodes/ruby-mode.el
@@ -1490,7 +1490,7 @@ With ARG, do it many times.  Negative ARG means move backward."
             (cond ((looking-at "\\?\\(\\\\[CM]-\\)*\\\\?\\S ")
                    (goto-char (match-end 0)))
                   ((progn
-                     (skip-chars-forward ",.:;|&^~=!?\\+\\-\\*")
+                     (skip-chars-forward "-,.:;|&^~=!?+*")
                      (looking-at "\\s("))
                    (goto-char (scan-sexps (point) 1)))
                   ((and (looking-at (concat "\\<\\(" ruby-block-beg-re
@@ -1533,7 +1533,7 @@ With ARG, do it many times.  Negative ARG means move forward."
     (let ((i (or arg 1)))
       (condition-case nil
           (while (> i 0)
-            (skip-chars-backward " \t\n,.:;|&^~=!?\\+\\-\\*")
+            (skip-chars-backward "- \t\n,.:;|&^~=!?+*")
             (forward-char -1)
             (cond ((looking-at "\\s)")
                    (goto-char (scan-sexps (1+ (point)) -1))
@@ -1546,7 +1546,7 @@ With ARG, do it many times.  Negative ARG means move forward."
                   ((looking-at "\\s\"\\|\\\\\\S_")
                    (let ((c (char-to-string (char-before (match-end 0)))))
                      (while (and (search-backward c)
-				 (eq (logand (skip-chars-backward "\\") 1)
+				 (eq (logand (skip-chars-backward "\\\\") 1)
 				     1))))
                    nil)
                   ((looking-at "\\s.\\|\\s\\")
diff --git a/lisp/progmodes/verilog-mode.el b/lisp/progmodes/verilog-mode.el
index f9c3177be41..9e241c70e76 100644
--- a/lisp/progmodes/verilog-mode.el
+++ b/lisp/progmodes/verilog-mode.el
@@ -10494,7 +10494,7 @@ Presumes that any newlines end a list element."
 		      (looking-at "[(,]")))
                (not (save-excursion  ; Not `endif, or user define
 		      (backward-char 1)
-		      (skip-chars-backward "[a-zA-Z0-9_`]")
+		      (skip-chars-backward "a-zA-Z0-9_`")
 		      (looking-at "`"))))
       (insert ","))))
 
diff --git a/lisp/term.el b/lisp/term.el
index 693362cc734..586a887a29f 100644
--- a/lisp/term.el
+++ b/lisp/term.el
@@ -1984,8 +1984,8 @@ A useful command to bind to SPC.  See `term-replace-by-expanded-history'."
 (defun term-within-quotes (beg end)
   "Return t if the number of quotes between BEG and END is odd.
 Quotes are single and double."
-  (let ((countsq (term-how-many-region "\\(^\\|[^\\\\]\\)'" beg end))
-	(countdq (term-how-many-region "\\(^\\|[^\\\\]\\)\"" beg end)))
+  (let ((countsq (term-how-many-region "\\(^\\|[^\\]\\)'" beg end))
+	(countdq (term-how-many-region "\\(^\\|[^\\]\\)\"" beg end)))
     (or (= (mod countsq 2) 1) (= (mod countdq 2) 1))))
 
 (defun term-how-many-region (regexp beg end)
diff --git a/lisp/textmodes/bib-mode.el b/lisp/textmodes/bib-mode.el
index 81dfb6c99c0..7a5d3ef7758 100644
--- a/lisp/textmodes/bib-mode.el
+++ b/lisp/textmodes/bib-mode.el
@@ -198,7 +198,7 @@ named by variable `unread-bib-file'."
 
 (defvar bib-capitalize-title-stop-words
    (concat
-      "the\\|and\\|of\\|is\\|a\\|an\\|of\\|for\\|in\\|to\\|in\\|on\\|at\\|"
+      "the\\|and\\|of\\|is\\|a\\|an\\|for\\|in\\|to\\|on\\|at\\|"
       "by\\|with\\|that\\|its")
    "Words not to be capitalized in a title (unless the first word).")
 
diff --git a/lisp/textmodes/refbib.el b/lisp/textmodes/refbib.el
index f8013c73bb2..3ba52e61ea6 100644
--- a/lisp/textmodes/refbib.el
+++ b/lisp/textmodes/refbib.el
@@ -137,7 +137,7 @@ This is in addition to the `r2b-capitalize-title-stop-words'.")
 
 (defvar r2b-capitalize-title-stop-words
    (concat
-      "the\\|and\\|of\\|is\\|a\\|an\\|of\\|for\\|in\\|to\\|in\\|on\\|at\\|"
+      "the\\|and\\|of\\|is\\|a\\|an\\|for\\|in\\|to\\|on\\|at\\|"
       "by\\|with\\|that\\|its")
    "Words not to be capitalized in a title (unless the first word).")
 
diff --git a/lisp/textmodes/reftex-parse.el b/lisp/textmodes/reftex-parse.el
index 2f9b7268fc8..005816e9659 100644
--- a/lisp/textmodes/reftex-parse.el
+++ b/lisp/textmodes/reftex-parse.el
@@ -1000,7 +1000,7 @@ OPT-ARGS is a list of argument numbers which are optional."
                     (eq (following-char) ?\{))
           (cl-incf cnt)))
       (if (and (= n cnt)
-               (> (skip-chars-forward "{\\[") 0))
+               (> (skip-chars-forward "{[") 0))
           (reftex-context-substring)
         nil))))
 
diff --git a/lisp/textmodes/rst.el b/lisp/textmodes/rst.el
index 0fc2f170a67..ba5d7e4f46f 100644
--- a/lisp/textmodes/rst.el
+++ b/lisp/textmodes/rst.el
@@ -225,7 +225,7 @@ and before TAIL-RE and DELIM-RE in VAR or DEFAULT for no match."
   "The SVN revision of this file.
 SVN revision is the upstream (docutils) revision.")
 (defconst rst-svn-timestamp
-  (rst-extract-version "\\$" "LastChangedDate: " ".+?+" " "
+  (rst-extract-version "\\$" "LastChangedDate: " ".+" " "
 		       "$LastChangedDate: 2017-01-08 10:54:35 +0100 (Sun, 08 Jan 2017) $")
   "The SVN time stamp of this file.")
 
diff --git a/lisp/url/url-http.el b/lisp/url/url-http.el
index 651a2cc94c6..46baa8a1482 100644
--- a/lisp/url/url-http.el
+++ b/lisp/url/url-http.el
@@ -513,7 +513,7 @@ Return the number of characters removed."
   (url-http-debug "url-http-parse-response called in (%s)" (buffer-name))
   (goto-char (point-min))
   (skip-chars-forward " \t\n")		; Skip any blank crap
-  (skip-chars-forward "HTTP/")		; Skip HTTP Version
+  (skip-chars-forward "/HPT")		; Skip HTTP Version "HTTP/".
   (setq url-http-response-version
 	(buffer-substring (point)
 			  (progn
diff --git a/test/lisp/progmodes/f90-tests.el b/test/lisp/progmodes/f90-tests.el
index 3cd7392bbc4..b1642388413 100644
--- a/test/lisp/progmodes/f90-tests.el
+++ b/test/lisp/progmodes/f90-tests.el
@@ -98,7 +98,7 @@ end subroutine test")
     (insert "(/ x /)")
     (f90-do-auto-fill)
     (beginning-of-line)
-    (skip-chars-forward "[ \t]")
+    (skip-chars-forward " \t")
     (should (equal "&(/" (buffer-substring (point) (+ 3 (point)))))))
 
 ;; TODO bug#5593