Fix bugs, inefficiencies and bad style in regexps

Found by relint.  See discussion at
https://lists.gnu.org/archive/html/emacs-devel/2020-04/msg00265.html

* lisp/org/org-table.el (org-table-finish-edit-field):
* lisp/arc-mode.el (archive-rar-summarize):
Avoid wrapped subsumption in repeated sequences.
* lisp/erc/erc-dcc.el (erc-dcc-ctcp-query-send-regexp): Replace
inefficient repeated empty-matching expression with a plain greedy
form.
(erc-dcc-handle-ctcp-send): Adjust group numbers.
* lisp/net/puny.el (puny-encode-domain): Fix fast-path shortcut
pattern so that it actually works as intended.
* lisp/progmodes/gdb-mi.el (gdb-control-commands-regexp):
* lisp/vc/diff-mode.el (diff-imenu-generic-expression):
Remove superfluous backslashes.
* lisp/progmodes/scheme.el (scheme-imenu-generic-expression):
Correct confused definition-matching pattern which would match more
than intended.
* lisp/textmodes/sgml-mode.el (sgml-tag-name-re): Avoid inefficient
matching by using the fact that the first character cannot match the
last char of sgml-name-re.

1 files changed, 7 insertions, 7 deletions

diff --git a/lisp/erc/erc-dcc.el b/lisp/erc/erc-dcc.el
index 26701cec1e4..8ccceec4594 100644
--- a/lisp/erc/erc-dcc.el
+++ b/lisp/erc/erc-dcc.el
@@ -627,11 +627,11 @@ that subcommand."
        ?q query ?n nick ?u login ?h host))))
 
 (defconst erc-dcc-ctcp-query-send-regexp
-  (concat "^DCC SEND \\("
+  (concat "^DCC SEND \\(?:"
           ;; Following part matches either filename without spaces
           ;; or filename enclosed in double quotes with any number
           ;; of escaped double quotes inside.
-          "\"\\(\\(.*?\\(\\\\\"\\)?\\)+?\\)\"\\|\\([^ ]+\\)"
+          "\"\\(\\(?:\\\\\"\\|[^\"\\]\\)+\\)\"\\|\\([^ ]+\\)"
           "\\) \\([0-9]+\\) \\([0-9]+\\) *\\([0-9]*\\)"))
 
 (define-inline erc-dcc-unquote-filename (filename)
@@ -653,11 +653,11 @@ It extracts the information about the dcc request and adds it to
        ?r "SEND" ?n nick ?u login ?h host))
      ((string-match erc-dcc-ctcp-query-send-regexp query)
       (let ((filename
-             (or (match-string 5 query)
-                 (erc-dcc-unquote-filename (match-string 2 query))))
-            (ip       (erc-decimal-to-ip (match-string 6 query)))
-            (port     (match-string 7 query))
-            (size     (match-string 8 query)))
+             (or (match-string 2 query)
+                 (erc-dcc-unquote-filename (match-string 1 query))))
+            (ip       (erc-decimal-to-ip (match-string 3 query)))
+            (port     (match-string 4 query))
+            (size     (match-string 5 query)))
         ;; FIXME: a warning really should also be sent
         ;; if the ip address != the host the dcc sender is on.
         (erc-display-message