From: Stefan Monnier <monnier@iro.umontreal.ca>
Date: Tue, 21 Apr 2015 01:55:00 +0000 (-0400)
Subject: Fix byte-compiler warnings about looking-back.
X-Git-Tag: emacs-25.0.90~2346
X-Git-Url: https://code.delx.au/gnu-emacs/commitdiff_plain/c9a75a4030a556d700fd95222ec0bf4c1a9f67b5

Fix byte-compiler warnings about looking-back.

* lisp/vc/log-view.el (log-view-end-of-defun-1):
* lisp/textmodes/tex-mode.el (latex-forward-sexp-1):
* lisp/textmodes/reftex-ref.el (reftex-goto-label):
* lisp/textmodes/bibtex.el (bibtex-insert-kill):
* lisp/progmodes/sh-script.el (sh--maybe-here-document):
* lisp/progmodes/ruby-mode.el (ruby-end-of-defun):
* lisp/progmodes/ada-mode.el (ada-in-numeric-literal-p):
* lisp/org/org.el (org-insert-heading, org-sort-entries):
* lisp/org/org-mouse.el (org-mouse-end-headline)
(org-mouse-context-menu):
* lisp/org/org-clock.el (org-clock-cancel):
* lisp/man.el (Man-default-man-entry):
* lisp/mail/rmail.el (rmail-get-new-mail, rmail-insert-inbox-text)
(rmail-ensure-blank-line):
* lisp/mail/footnote.el (Footnote-delete-footnote):
* lisp/mail/emacsbug.el (report-emacs-bug):
* lisp/info.el (Info-follow-reference, Info-fontify-node):
* lisp/info-look.el (info-lookup-guess-custom-symbol):
* lisp/help-fns.el (help-fns--key-bindings):
* lisp/files.el (hack-local-variables):
* lisp/emulation/viper-ex.el (viper-get-ex-token, ex-cmd-complete)
(viper-get-ex-pat, ex-expand-filsyms, viper-get-ex-file)
(viper-complete-filename-or-exit):
* lisp/emulation/viper-cmd.el (viper-backward-indent):
* lisp/emacs-lisp/lisp-mode.el (calculate-lisp-indent):
* lisp/emacs-lisp/elint.el (elint-get-top-forms):
* lisp/cus-edit.el (custom-face-edit-value-create):
* lisp/calendar/todo-mode.el (todo-set-item-priority)
(todo-filter-items-1, todo-convert-legacy-files)
(todo-prefix-overlays): Add explicit second arg to looking-back.
---

diff --git a/etc/NEWS b/etc/NEWS
index 9dd0e1512c..804b819a8b 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -233,7 +233,9 @@ Unicode standards.
 
 * Changes in Specialized Modes and Packages in Emacs 25.1
 ** In xterms, killing text now also sets the CLIPBOARD/PRIMARY selection
-in the surrounding GUI (using the OSC-52 escape sequence).
+in the surrounding GUI (using the OSC-52 escape sequence).  This only works
+if your xterm supports it and enables the `allowWindowOps' options (disabled
+by default at least in Debian, for security reasons).
 
 ** xterm-mouse-mode now supports mouse-tracking (if your xterm supports it).
 
diff --git a/lisp/calendar/todo-mode.el b/lisp/calendar/todo-mode.el
index dcc960fb9b..bb9316c81d 100644
--- a/lisp/calendar/todo-mode.el
+++ b/lisp/calendar/todo-mode.el
@@ -2606,7 +2606,8 @@ meaning to raise or lower the item's priority by one."
 	    ;; separator.
 	    (when (looking-back (concat "^"
 					(regexp-quote todo-category-done)
-					"\n"))
+					"\n")
+                                (line-beginning-position 0))
 	      (todo-backward-item))))
 	(todo-insert-with-overlays item)
 	;; If item was marked, restore the mark.
@@ -4231,7 +4232,8 @@ the values of FILTER and FILE-LIST."
 			   (if (and (eobp)
 				    (looking-back
 				     (concat (regexp-quote todo-done-string)
-					     "\n")))
+					     "\n")
+                                     (line-beginning-position 0)))
 			       (delete-region (point) (progn
 							(forward-line -2)
 							(point))))))
@@ -4648,7 +4650,7 @@ name in `todo-directory'.  See also the documentation string of
 		;; If the item ends with a non-comment parenthesis not
 		;; followed by a period, we lose (but we inherit that
 		;; problem from the legacy code).
-		(when (looking-back "(\\(.*\\)) ")
+		(when (looking-back "(\\(.*\\)) " (line-beginning-position))
 		  (setq comment (match-string 1))
 		  (replace-match "")
 		  (insert "[" todo-comment-string ": " comment "]"))
@@ -5342,7 +5344,8 @@ of each other."
 		     (looking-at todo-done-string-start)
 		     (looking-back (concat "^"
 					   (regexp-quote todo-category-done)
-					   "\n")))
+					   "\n")
+                                   (line-beginning-position 0)))
 	    (setq num 1
 		  done t))
 	  (setq prefix (concat (propertize
diff --git a/lisp/cus-edit.el b/lisp/cus-edit.el
index 9cc2fa81d0..cd894f4726 100644
--- a/lisp/cus-edit.el
+++ b/lisp/cus-edit.el
@@ -3115,7 +3115,7 @@ face attributes (as specified by a `default' defface entry)."
 		    widget
 		    (widget-get widget :default-face-attributes)))
 	 entry)
-    (unless (looking-back "^ *")
+    (unless (looking-back "^ *" (line-beginning-position))
       (insert ?\n))
     (insert-char ?\s (widget-get widget :extra-offset))
     (if (or alist defaults show-all)
diff --git a/lisp/emacs-lisp/elint.el b/lisp/emacs-lisp/elint.el
index 136467046b..317e5a6fd3 100644
--- a/lisp/emacs-lisp/elint.el
+++ b/lisp/emacs-lisp/elint.el
@@ -374,7 +374,7 @@ Returns the forms."
 	(let ((elint-current-pos (point)))
 	  ;; non-list check could be here too. errors may be out of seq.
 	  ;; quoted check cannot be elsewhere, since quotes skipped.
-	  (if (looking-back "'")
+	  (if (looking-back "'" (1- (point)))
 	      ;; Eg cust-print.el uses ' as a comment syntax.
 	      (elint-warning "Skipping quoted form `'%.20s...'"
 			   (read (current-buffer)))
diff --git a/lisp/emacs-lisp/lisp-mnt.el b/lisp/emacs-lisp/lisp-mnt.el
index fec172d05c..104c23c210 100644
--- a/lisp/emacs-lisp/lisp-mnt.el
+++ b/lisp/emacs-lisp/lisp-mnt.el
@@ -437,9 +437,9 @@ This can be found in an RCS or SCCS header."
 	   ((re-search-forward
 	     (concat
 	      "@(#)"
-	      (if buffer-file-name
+              (if buffer-file-name
                   (regexp-quote (file-name-nondirectory buffer-file-name))
-                "[^\t\n]*")
+                "[^\t\n]+")
 	      "\t\\([012345679.]*\\)")
 	     header-max t)
 	    (match-string-no-properties 1)))))))
diff --git a/lisp/emacs-lisp/lisp-mode.el b/lisp/emacs-lisp/lisp-mode.el
index 26a21d5237..108d5ccb0e 100644
--- a/lisp/emacs-lisp/lisp-mode.el
+++ b/lisp/emacs-lisp/lisp-mode.el
@@ -855,9 +855,10 @@ is the buffer position of the start of the containing expression."
 		       ;; Handle prefix characters and whitespace
 		       ;; following an open paren.  (Bug#1012)
                        (backward-prefix-chars)
-                       (while (and (not (looking-back "^[ \t]*\\|([ \t]+"))
-                                   (or (not containing-sexp)
-                                       (< (1+ containing-sexp) (point))))
+                       (while (not (or (looking-back "^[ \t]*\\|([ \t]+"
+                                                      (line-beginning-position))
+                                       (and containing-sexp
+                                            (>= (1+ containing-sexp) (point)))))
                          (forward-sexp -1)
                          (backward-prefix-chars))
                        (setq calculate-lisp-indent-last-sexp (point)))
diff --git a/lisp/emulation/viper-cmd.el b/lisp/emulation/viper-cmd.el
index bd03a870fd..5c91df9016 100644
--- a/lisp/emulation/viper-cmd.el
+++ b/lisp/emulation/viper-cmd.el
@@ -4533,7 +4533,7 @@ One can use `` and '' to temporarily jump 1 step back."
   (interactive)
   (if viper-cted
       (let ((p (point)) (c (current-column)) bol (indent t))
-	(if (looking-back "[0^]")
+	(if (looking-back "[0^]" (1- (point)))
 	    (progn
 	      (if (eq ?^ (preceding-char))
 		  (setq viper-preserve-indent t))
@@ -4545,7 +4545,7 @@ One can use `` and '' to temporarily jump 1 step back."
 	(delete-region (point) p)
 	(if indent
 	    (indent-to (- c viper-shift-width)))
-	(if (or (bolp) (looking-back "[^ \t]"))
+	(if (or (bolp) (looking-back "[^ \t]" (1- (point))))
 	    (setq viper-cted nil)))))
 
 ;; do smart indent
diff --git a/lisp/emulation/viper-ex.el b/lisp/emulation/viper-ex.el
index 212f0533b8..e6bcf8f89a 100644
--- a/lisp/emulation/viper-ex.el
+++ b/lisp/emulation/viper-ex.el
@@ -455,7 +455,8 @@ reversed."
 	       (while (and (not (eolp)) cont)
 		 ;;(re-search-forward "[^/]*/")
 		 (re-search-forward "[^/]*\\(/\\|\n\\)")
-		 (if (not (looking-back "[^\\\\]\\(\\\\\\\\\\)*\\\\/"))
+		 (if (not (looking-back "[^\\\\]\\(\\\\\\\\\\)*\\\\/"
+                                        (line-beginning-position 0)))
 		     (setq cont nil))))
 	     (backward-char 1)
 	     (setq ex-token (buffer-substring (point) (mark t)))
@@ -468,7 +469,8 @@ reversed."
 	       (while (and (not (eolp)) cont)
 		 ;;(re-search-forward "[^\\?]*\\?")
 		 (re-search-forward "[^\\?]*\\(\\?\\|\n\\)")
-		 (if (not (looking-back "[^\\\\]\\(\\\\\\\\\\)*\\\\\\?"))
+		 (if (not (looking-back "[^\\\\]\\(\\\\\\\\\\)*\\\\\\?"
+                                        (line-beginning-position 0)))
 		     (setq cont nil))
 		 (backward-char 1)
 		 (if (not (looking-at "\n")) (forward-char 1))))
@@ -563,14 +565,18 @@ reversed."
 	    save-pos (point)))
 
     (if (or (= dist 0)
-	    (looking-back "\\([ \t]*['`][ \t]*[a-z]*\\)")
+	    (looking-back "\\([ \t]*['`][ \t]*[a-z]*\\)"
+                          (line-beginning-position))
 	    (looking-back
-	     "^[ \t]*[a-zA-Z!=>&~][ \t]*[/?]*[ \t]+[a-zA-Z!=>&~]+"))
+	     "^[ \t]*[a-zA-Z!=>&~][ \t]*[/?]*[ \t]+[a-zA-Z!=>&~]+"
+             (line-beginning-position)))
 	;; Preceding characters are not the ones allowed in an Ex command
 	;; or we have typed past command name.
 	;; Note: we didn't do parsing, so there can be surprises.
-	(if (or (looking-back "[a-zA-Z!=>&~][ \t]*[/?]*[ \t]*")
-		(looking-back "\\([ \t]*['`][ \t]*[a-z]*\\)")
+	(if (or (looking-back "[a-zA-Z!=>&~][ \t]*[/?]*[ \t]*"
+                              (line-beginning-position))
+		(looking-back "\\([ \t]*['`][ \t]*[a-z]*\\)"
+                              (line-beginning-position))
 		(looking-at "[^ \t\n\C-m]"))
 	    nil
 	  (with-output-to-temp-buffer "*Completions*"
@@ -747,7 +753,8 @@ reversed."
 			(error "Missing closing delimiter for global regexp")
 		      (goto-char (point-max))))
 		(if (not (looking-back
-			  (format "[^\\\\]\\(\\\\\\\\\\)*\\\\%c" c)))
+			  (format "[^\\\\]\\(\\\\\\\\\\)*\\\\%c" c)
+                          (line-beginning-position 0)))
 		    (setq cont nil)
 		  ;; we are at an escaped delimiter: unescape it and continue
 		  (delete-char -2)
@@ -963,7 +970,7 @@ reversed."
       (while (re-search-forward "%\\|#" nil t)
 	(let ((data (match-data))
 	      (char (buffer-substring (match-beginning 0) (match-end 0))))
-	  (if (looking-back (concat "\\\\" char))
+	  (if (looking-back "\\\\." (- (point) 2))
 	      (replace-match char)
 	    (store-match-data data)
 	    (if (string= char "%")
@@ -989,7 +996,7 @@ reversed."
                                  (get-buffer-create viper-ex-work-buf-name))
 	(skip-chars-forward " \t")
 	(if (looking-at "!")
-	    (if (and (not (looking-back "[ \t]"))
+	    (if (and (not (looking-back "[ \t]" (1- (point))))
 		     ;; read doesn't have a corresponding :r! form, so ! is
 		     ;; immediately interpreted as a shell command.
 		     (not (string= ex-token "read")))
@@ -1066,7 +1073,7 @@ reversed."
   (cond ((ex-cmd-accepts-multiple-files-p ex-token) (exit-minibuffer))
 	;; apparently the argument to an Ex command is
 	;; supposed to be a shell command
-	((looking-back "^[ \t]*!.*")
+	((looking-back "^[ \t]*!.*" (line-beginning-position))
 	 (setq ex-cmdfile t)
 	 (insert " "))
 	(t
diff --git a/lisp/files.el b/lisp/files.el
index 0b011f4c36..152f155427 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -3375,7 +3375,7 @@ local variables, but directory-local variables may still be applied."
 		      (error "Local variables entry is missing the prefix"))
 		    (end-of-line)
 		    ;; Discard the suffix.
-		    (if (looking-back suffix)
+		    (if (looking-back suffix (line-beginning-position))
 			(delete-region (match-beginning 0) (point))
 		      (error "Local variables entry is missing the suffix"))
 		    (forward-line 1))
diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index 7ecd271d0c..53f4b38b9e 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -329,7 +329,7 @@ suitable file is found, return nil."
 
       (with-current-buffer standard-output
         (fill-region-as-paragraph pt2 (point))
-        (unless (looking-back "\n\n")
+        (unless (looking-back "\n\n" (- (point) 2))
           (terpri))))))
 
 (defun help-fns--compiler-macro (function)
diff --git a/lisp/info-look.el b/lisp/info-look.el
index 9cf185edf5..8a86dc8168 100644
--- a/lisp/info-look.el
+++ b/lisp/info-look.el
@@ -634,7 +634,8 @@ Return nil if there is nothing appropriate in the buffer near point."
 		     (setq end (point))
 		     (> end beg))
 		(and (looking-at "[ \t\n]")
-		     (looking-back (concat "[" significant-chars "]"))
+		     (looking-back (concat "[" significant-chars "]")
+                                   (1- (point)))
 		     (setq end (point))
 		     (skip-chars-backward significant-chars)
 		     (setq beg (point))
diff --git a/lisp/info.el b/lisp/info.el
index 0159661947..057bd77ba1 100644
--- a/lisp/info.el
+++ b/lisp/info.el
@@ -2577,7 +2577,9 @@ new buffer."
     (save-excursion
       ;; Move point to the beginning of reference if point is on reference
       (or (looking-at "\\*note[ \n\t]+")
-          (and (looking-back "\\*note[ \n\t]+")
+          (and (looking-back "\\*note[ \n\t]+"
+                             (save-excursion (skip-chars-backward " \n\t")
+                                             (line-beginning-position)))
                (goto-char (match-beginning 0)))
           (if (and (save-excursion
                      (goto-char (+ (point) 5)) ; skip a possible *note
@@ -4738,9 +4740,11 @@ first line or header line, and for breadcrumb links.")
 		    ;; an end of sentence
 		    (skip-syntax-backward " ("))
                   (setq other-tag
-			(cond ((save-match-data (looking-back "\\<see"))
+			(cond ((save-match-data (looking-back "\\<see"
+                                                              (- (point) 3)))
 			       "")
-			      ((save-match-data (looking-back "\\<in"))
+			      ((save-match-data (looking-back "\\<in"
+                                                              (- (point) 2)))
 			       "")
 			      ((memq (char-before) '(nil ?\. ?! ??))
                                "See ")
diff --git a/lisp/mail/emacsbug.el b/lisp/mail/emacsbug.el
index 8cd59006d8..f4ba2264dc 100644
--- a/lisp/mail/emacsbug.el
+++ b/lisp/mail/emacsbug.el
@@ -295,7 +295,7 @@ usually do not have translators for other languages.\n\n")))
 	    (insert-buffer-substring message-buf beg-pos end-pos))))
     ;; After Recent messages, to avoid the messages produced by
     ;; list-load-path-shadows.
-    (unless (looking-back "\n")
+    (unless (looking-back "\n" (1- (point)))
       (insert "\n"))
     (insert "\n")
     (insert "Load-path shadows:\n")
diff --git a/lisp/mail/footnote.el b/lisp/mail/footnote.el
index ea674434a2..86bb9e8961 100644
--- a/lisp/mail/footnote.el
+++ b/lisp/mail/footnote.el
@@ -718,7 +718,7 @@ delete the footnote with that number."
 					 end
 				       (point-max))))
 	    (Footnote-goto-char-point-max)
-	    (when (looking-back "\n\n")
+	    (when (looking-back "\n\n" (- (point) 2))
 	      (kill-line -1))))))))
 
 (defun Footnote-renumber-footnotes (&optional arg)
diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index d150324fc7..74533f88fd 100644
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -1787,7 +1787,7 @@ not be a new one).  It returns non-nil if it got any new messages."
 	      ;; Make sure we end with a blank line unless there are
 	      ;; no messages, as required by mbox format (Bug#9974).
 	      (unless (bobp)
-		(while (not (looking-back "\n\n"))
+		(while (not (looking-back "\n\n" (- (point) 2)))
 		  (insert "\n")))
 	      (setq found (or
 			   (rmail-get-new-mail-1 file-name files delete-files)
@@ -2092,7 +2092,7 @@ Value is the size of the newly read mail after conversion."
 	    ;; Make sure the read-in mbox data properly ends with a
 	    ;; blank line unless it is of size 0.
 	    (unless (zerop size)
-	      (while (not (looking-back "\n\n"))
+	      (while (not (looking-back "\n\n" (- (point) 2)))
 		(insert "\n")))
 	    (if (not (and rmail-preserve-inbox (string= file tofile)))
 		(setq delete-files (cons tofile delete-files)))))
@@ -2127,7 +2127,7 @@ Value is the size of the newly read mail after conversion."
 Call with point at the end of the message."
   (unless (bolp)
     (insert "\n"))
-  (unless (looking-back "\n\n")
+  (unless (looking-back "\n\n" (- (point 2)))
     (insert "\n")))
 
 (defun rmail-add-mbox-headers ()
diff --git a/lisp/man.el b/lisp/man.el
index d9124c24e0..c5dbcba83a 100644
--- a/lisp/man.el
+++ b/lisp/man.el
@@ -747,7 +747,8 @@ POS defaults to `point'."
 	  ;; Record the distance traveled.
 	  (setq distance (- column (current-column)))
 	  (when (looking-back
-		 (concat "([ \t]*\\(?:" Man-section-regexp "\\)[ \t]*)"))
+		 (concat "([ \t]*\\(?:" Man-section-regexp "\\)[ \t]*)")
+                 (line-beginning-position))
 	    ;; Skip section number backwards.
 	    (goto-char (match-beginning 0))
 	    (skip-chars-backward " \t"))
diff --git a/lisp/org/org-clock.el b/lisp/org/org-clock.el
index 41e799f989..c0a45b3ad1 100644
--- a/lisp/org/org-clock.el
+++ b/lisp/org/org-clock.el
@@ -1656,7 +1656,8 @@ Optional argument N tells to change by that many units."
   (save-excursion ; Do not replace this with `with-current-buffer'.
     (org-no-warnings (set-buffer (org-clocking-buffer)))
     (goto-char org-clock-marker)
-    (if (org-looking-back (concat "^[ \t]*" org-clock-string ".*"))
+    (if (org-looking-back (concat "^[ \t]*" org-clock-string ".*")
+                          (line-beginning-position))
 	(progn (delete-region (1- (point-at-bol)) (point-at-eol))
 	       (org-remove-empty-drawer-at "LOGBOOK" (point)))
       (message "Clock gone, cancel the timer anyway")
diff --git a/lisp/org/org-mouse.el b/lisp/org/org-mouse.el
index 160099ff05..9b218147b6 100644
--- a/lisp/org/org-mouse.el
+++ b/lisp/org/org-mouse.el
@@ -191,7 +191,7 @@ Changing this variable requires a restart of Emacs to get activated."
   (interactive)
   (end-of-line)
   (skip-chars-backward "\t ")
-  (when (org-looking-back ":[A-Za-z]+:")
+  (when (org-looking-back ":[A-Za-z]+:" (line-beginning-position))
     (skip-chars-backward ":A-Za-z")
     (skip-chars-backward "\t ")))
 
@@ -645,7 +645,7 @@ This means, between the beginning of line and the point."
 					'org-mode-restart))))
      ((or (eolp)
 	  (and (looking-at "\\(  \\|\t\\)\\(+:[0-9a-zA-Z_:]+\\)?\\(  \\|\t\\)+$")
-	       (org-looking-back "  \\|\t")))
+	       (org-looking-back "  \\|\t" (- (point) 2))))
       (org-mouse-popup-global-menu))
      ((funcall get-context :checkbox)
       (popup-menu
diff --git a/lisp/org/org.el b/lisp/org/org.el
index 3e032d4664..54924a9964 100644
--- a/lisp/org/org.el
+++ b/lisp/org/org.el
@@ -7679,7 +7679,7 @@ command."
 	      (re-search-forward org-outline-regexp-bol)
 	      (beginning-of-line 0))
 	    (skip-chars-backward " \r\n")
-	    (and (not (looking-back "^\*+"))
+	    (and (not (looking-back "^\*+" (line-beginning-position)))
 		 (looking-at "[ \t]+") (replace-match ""))
 	    (unless (eobp) (forward-char 1))
 	    (when (looking-at "^\\*")
@@ -8658,7 +8658,8 @@ links."
 	 (when (equal (marker-buffer org-clock-marker) (current-buffer))
 	   (save-excursion
 	     (goto-char org-clock-marker)
-	     (looking-back "^.*") (match-string-no-properties 0))))
+             (buffer-substring-no-properties (line-beginning-position)
+                                             (point)))))
         start beg end stars re re2
         txt what tmp)
     ;; Find beginning and end of region to sort
diff --git a/lisp/progmodes/ada-mode.el b/lisp/progmodes/ada-mode.el
index 8afb92f2c9..c1bc79c599 100644
--- a/lisp/progmodes/ada-mode.el
+++ b/lisp/progmodes/ada-mode.el
@@ -1013,7 +1013,7 @@ If PARSE-RESULT is non-nil, use it instead of calling `parse-partial-sexp'."
 
 (defsubst ada-in-numeric-literal-p ()
   "Return t if point is after a prefix of a numeric literal."
-  (looking-back "\\([0-9]+#[0-9a-fA-F_]+\\)"))
+  (looking-back "\\([0-9]+#[0-9a-fA-F_]+\\)" (line-beginning-position)))
 
 ;;------------------------------------------------------------------
 ;; Contextual menus
diff --git a/lisp/progmodes/ruby-mode.el b/lisp/progmodes/ruby-mode.el
index f2fb95ce59..0e2f66e5bc 100644
--- a/lisp/progmodes/ruby-mode.el
+++ b/lisp/progmodes/ruby-mode.el
@@ -1392,7 +1392,8 @@ by `end-of-defun'."
   (interactive "p")
   (ruby-forward-sexp)
   (let (case-fold-search)
-    (when (looking-back (concat "^\\s *" ruby-block-end-re))
+    (when (looking-back (concat "^\\s *" ruby-block-end-re)
+                        (line-beginning-position))
       (forward-line 1))))
 
 (defun ruby-beginning-of-indent ()
diff --git a/lisp/progmodes/sh-script.el b/lisp/progmodes/sh-script.el
index 135f945dbb..e4d16eb0ab 100644
--- a/lisp/progmodes/sh-script.el
+++ b/lisp/progmodes/sh-script.el
@@ -4344,7 +4344,7 @@ The document is bounded by `sh-here-document-word'."
   (or arg (sh--maybe-here-document)))
 
 (defun sh--maybe-here-document ()
-  (or (not (looking-back "[^<]<<"))
+  (or (not (looking-back "[^<]<<" (line-beginning-position)))
       (save-excursion
 	(backward-char 2)
         (or (sh-quoted-p)
diff --git a/lisp/textmodes/bibtex.el b/lisp/textmodes/bibtex.el
index 5933559b37..8a018520f5 100644
--- a/lisp/textmodes/bibtex.el
+++ b/lisp/textmodes/bibtex.el
@@ -2229,7 +2229,7 @@ Optional arg COMMA is as in `bibtex-enclosing-field'."
                        bibtex-entry-kill-ring))
       ;; If we copied an entry from a buffer containing only this one entry,
       ;; it can be missing the second "\n".
-      (unless (looking-back "\n\n") (insert "\n"))
+      (unless (looking-back "\n\n" (- (point 2))) (insert "\n"))
       (unless (functionp bibtex-reference-keys)
         ;; update `bibtex-reference-keys'
         (save-excursion
diff --git a/lisp/textmodes/reftex-ref.el b/lisp/textmodes/reftex-ref.el
index be119d9db5..d0e09bff88 100644
--- a/lisp/textmodes/reftex-ref.el
+++ b/lisp/textmodes/reftex-ref.el
@@ -857,7 +857,8 @@ Optional prefix argument OTHER-WINDOW goes to the label in another window."
          (docstruct (symbol-value reftex-docstruct-symbol))
 	 ;; If point is inside a \ref{} or \pageref{}, use that as
 	 ;; default value.
-	 (default (when (looking-back "\\\\\\(?:page\\)?ref{[-a-zA-Z0-9_*.:]*")
+	 (default (when (looking-back "\\\\\\(?:page\\)?ref{[-a-zA-Z0-9_*.:]*"
+                                      (line-beginning-position))
 		    (reftex-this-word "-a-zA-Z0-9_*.:")))
          (label (completing-read (if default
 				     (format "Label (default %s): " default)
diff --git a/lisp/textmodes/tex-mode.el b/lisp/textmodes/tex-mode.el
index e9c7e2f114..c26c609836 100644
--- a/lisp/textmodes/tex-mode.el
+++ b/lisp/textmodes/tex-mode.el
@@ -1761,13 +1761,13 @@ Mark is left at original location."
        ;; A better way to handle this, \( .. \) etc, is probably to
        ;; temporarily change the syntax of the \ in \( to punctuation.
        ((and latex-handle-escaped-parens
-	     (looking-back "\\\\[])}]"))
+	     (looking-back "\\\\[])}]" (- (point) 2)))
 	(signal 'scan-error
 		(list "Containing expression ends prematurely"
 		      (- (point) 2) (prog1 (point)
 				      (goto-char pos)))))
        ((and latex-handle-escaped-parens
-	     (looking-back "\\\\\\([({[]\\)"))
+	     (looking-back "\\\\\\([({[]\\)" (- (point) 2)))
 	(tex-next-unmatched-eparen (match-string 1)))
        (t (goto-char newpos))))))
 
diff --git a/lisp/vc/log-view.el b/lisp/vc/log-view.el
index 98e9357220..042ea131a9 100644
--- a/lisp/vc/log-view.el
+++ b/lisp/vc/log-view.el
@@ -466,7 +466,8 @@ It assumes that a log entry starts with a line matching
 	  (goto-char (match-beginning 0))))
        ;; Don't advance past the end buttons inserted by
        ;; `vc-print-log-setup-buttons'.
-       ((looking-back "Show 2X entries    Show unlimited entries")
+       ((looking-back "Show 2X entries    Show unlimited entries"
+                      (line-beginning-position))
 	(setq looping nil)
 	(forward-line -1))))))