Fix some ineffective backslashes in string literals

Deal with lone backslashes that have no effect in string literals,
but indicate that something is amiss.

* lisp/auth-source-pass.el (auth-source-pass-entries):
* lisp/textmodes/artist.el (artist-figlet-get-font-list-windows):
* lisp/org/ob-abc.el (org-babel-expand-body:abc, org-babel-execute:abc):
* lisp/org/ob-forth.el (org-babel-forth-session-execute):
* lisp/vc/vc-git.el (vc-git--program-version):
Add backslash in regexp for correctness.

* lisp/gnus/nnmail.el (nnmail-split-abbrev-alist):
Replace `\||' with `\\|' to follow the obvious regexp intent.

* lisp/org/org-list.el (org-plain-list-ordered-item-terminator):
Add backslash in doc comment so that it appears as intended.

* lisp/progmodes/cc-engine.el (c-forward-decl-or-cast-1, c-end-of-decl-1):
* lisp/progmodes/f90.el (f90-font-lock-keywords-2):
* lisp/progmodes/etags.el (etags-tags-completion-table):
* lisp/progmodes/ruby-mode.el (ruby-syntax-propertize):
* test/lisp/emacs-lisp/cl-print-tests.el (cl-print-tests-1):
Remove superfluous backslashes from regexp.

* test/lisp/emacs-lisp/rx-tests.el (rx-char-any):
Remove superfluous backslash from doc comment.

4 files changed, 6 insertions, 6 deletions

diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index fd669280994..cc3753a7ebd 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -8968,7 +8968,7 @@ This function might do hidden buffer changes."
 
 	 (setq at-decl-end
 	       (looking-at (cond ((eq context '<>) "[,>]")
-				 ((not (memq context '(nil top))) "[,\)]")
+				 ((not (memq context '(nil top))) "[,)]")
 				 (t "[,;]"))))
 
 	 ;; Now we've collected info about various characteristics of
@@ -10321,7 +10321,7 @@ comment at the start of cc-engine.el for more info."
 			  ;; Check for `c-opt-block-decls-with-vars-key'
 			  ;; before the first paren.
 			  (c-syntactic-re-search-forward
-			   (concat "[;=\(\[{]\\|\\("
+			   (concat "[;=([{]\\|\\("
 				   c-opt-block-decls-with-vars-key
 				   "\\)")
 			   lim t t t)
@@ -10329,7 +10329,7 @@ comment at the start of cc-engine.el for more info."
 			  (not (eq (char-before) ?_))
 			  ;; Check that the first following paren is
 			  ;; the block.
-			  (c-syntactic-re-search-forward "[;=\(\[{]"
+			  (c-syntactic-re-search-forward "[;=([{]"
 							 lim t t t)
 			  (eq (char-before) ?{))))))
 	    ;; The declaration doesn't have any of the
diff --git a/lisp/progmodes/etags.el b/lisp/progmodes/etags.el
index c2715be5370..910c320ab8f 100644
--- a/lisp/progmodes/etags.el
+++ b/lisp/progmodes/etags.el
@@ -1281,7 +1281,7 @@ buffer-local values of tags table format variables."
       ;; This regexp matches an explicit tag name or the place where
       ;; it would start.
       (while (re-search-forward
-              "[\f\t\n\r()=,; ]?\177\\\(?:\\([^\n\001]+\\)\001\\)?"
+              "[\f\t\n\r()=,; ]?\177\\(?:\\([^\n\001]+\\)\001\\)?"
 	      nil t)
 	(push	(prog1 (if (match-beginning 1)
 			   ;; There is an explicit tag name.
diff --git a/lisp/progmodes/f90.el b/lisp/progmodes/f90.el
index 3ec145b547e..9de80635e9f 100644
--- a/lisp/progmodes/f90.el
+++ b/lisp/progmodes/f90.el
@@ -648,7 +648,7 @@ forall\\|block\\|critical\\)\\)\\_>"
 \\|enumerator\\|procedure\\|\
 logical\\|double[ \t]*precision\\|type[ \t]*(\\(?:\\sw\\|\\s_\\)+)\\|none\\)[ \t]*"
       (1 font-lock-keyword-face) (2 font-lock-type-face))
-    '("\\_<\\(namelist\\|common\\)[ \t]*/\\(\\(?:\\sw\\|\\s_\\)+\\)?\/"
+    '("\\_<\\(namelist\\|common\\)[ \t]*/\\(\\(?:\\sw\\|\\s_\\)+\\)?/"
       (1 font-lock-keyword-face) (2 font-lock-constant-face nil t))
     "\\_<else\\([ \t]*if\\|where\\)?\\_>"
     '("\\(&\\)[ \t]*\\(!\\|$\\)"  (1 font-lock-keyword-face))
diff --git a/lisp/progmodes/ruby-mode.el b/lisp/progmodes/ruby-mode.el
index 707875d130d..5998ac8e395 100644
--- a/lisp/progmodes/ruby-mode.el
+++ b/lisp/progmodes/ruby-mode.el
@@ -1867,7 +1867,7 @@ It will be properly highlighted even when the call omits parens.")
       ("^[ \t]*def +\\(`\\)" (1 "_"))
       ;; Ternary operator colon followed by opening paren or bracket
       ;; (semi-important for indentation).
-      ("\\(:\\)\\(?:[\({]\\|\\[[^]]\\)"
+      ("\\(:\\)\\(?:[({]\\|\\[[^]]\\)"
        (1 (string-to-syntax ".")))
       ;; Regular expressions.  Start with matching unescaped slash.
       ("\\(?:\\=\\|[^\\]\\)\\(?:\\\\\\\\\\)*\\(/\\)"