Hello,

On the input pattern:
,,X

..the following substitute command,
   %s;\(^\|,\)\ze\(,\|X\);\1N;gc

..changes it to (type 'y' for all prompts):
N,N,NX

As expected. But if you type 'a' instead (for replace all), you get:
N,,NX

Executing
   %s;\(^\|,\)\ze\(,\|X\);\1N;g
behaves the same as typing 'a' with confirmation.

Another user (Marcin Szamotulski) adds:
Also the following pattern is behaving in this way:
%s;\(^\|,\)\(,\|X\)\@=;\1N;gc

:version
VIM - Vi IMproved 7.3 (2010 Aug 15, compiled May  4 2012 04:10:13)
Included patches: 1-429
Modified by <removed email address>
Compiled by buildd@
Huge version with GTK2 GUI.  Features included (+) or not (-):
+arabic +autocmd +balloon_eval +browse ++builtin_terms +byte_offset +cindent
+clientserver +clipboard +cmdline_compl +cmdline_hist +cmdline_info +comments
+conceal +cryptv +cscope +cursorbind +cursorshape +dialog_con_gui +diff
+digraphs +dnd -ebcdic +emacs_tags +eval +ex_extra +extra_search +farsi
+file_in_path +find_in_path +float +folding -footer +fork() +gettext
-hangul_input +iconv +insert_expand +jumplist +keymap +langmap +libcall
+linebreak +lispindent +listcmds +localmap +lua +menu +mksession +modify_fname
+mouse +mouseshape +mouse_dec +mouse_gpm -mouse_jsbterm +mouse_netterm
-mouse_sysmouse +mouse_xterm +mouse_urxvt +multi_byte +multi_lang -mzscheme
+netbeans_intg +path_extra +perl +persistent_undo +postscript +printer +profile
 +python -python3 +quickfix +reltime +rightleft +ruby +scrollbind +signs
+smartindent -sniff +startuptime +statusline -sun_workshop +syntax +tag_binary
+tag_old_static -tag_any_white +tcl +terminfo +termresponse +textobjects +title
 +toolbar +user_commands +vertsplit +virtualedit +visual +visualextra +viminfo
+vreplace +wildignore +wildmenu +windows +writebackup +X11 -xfontset +xim
+xsmp_interact +xterm_clipboard -xterm_save
   system vimrc file: "$VIM/vimrc"
     user vimrc file: "$HOME/.vimrc"
      user exrc file: "$HOME/.exrc"
  system gvimrc file: "$VIM/gvimrc"
    user gvimrc file: "$HOME/.gvimrc"
    system menu file: "$VIMRUNTIME/menu.vim"
  fall-back for $VIM: "/usr/share/vim"
Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H -DFEAT_GUI_GTK
-pthread -I/usr/include/gtk-2.0
-I/usr/lib/i386-linux-gnu/gtk-2.0/include -I/usr/include/atk-1.0
-I/usr/include/cairo -I/usr/include/gdk-pixbuf-2.0
-I/usr/include/pango-1.0 -I/usr/include/gio-unix-2.0/
-I/usr/include/glib-2.0 -I/usr/lib/i386-linux-gnu/glib-2.0/include
-I/usr/include/pixman-1 -I/usr/include/freetype2
-I/usr/include/libpng12     -g -O2 -fstack-protector
--param=ssp-buffer-size=4 -Wformat -Wformat-security
-Werror=format-security -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1
-I/usr/include/tcl8.5  -D_REENTRANT=1  -D_THREAD_SAFE=1
-D_LARGEFILE64_SOURCE=1
Linking: gcc   -L. -Wl,-Bsymbolic-functions -Wl,-z,relro -rdynamic
-Wl,-export-dynamic  -Wl,-E  -Wl,-Bsymbolic-functions -Wl,-z,relro
-Wl,--as-needed -o vim   -lgtk-x11-2.0 -lgdk-x11-2.0 -latk-1.0
-lgio-2.0 -lpangoft2-1.0 -lpangocairo-1.0 -lgdk_pixbuf-2.0 -lcairo
-lpango-1.0 -lfreetype -lfontconfig -lgobject-2.0 -lglib-2.0   -lSM
-lICE -lXpm -lXt -lX11 -lXdmcp -lSM -lICE -lm -ltinfo -lnsl  -lselinux
 -lacl -lattr -lgpm -ldl  -L/usr/lib -llua5.1  -Wl,-E
-fstack-protector -L/usr/local/lib  -L/usr/lib/perl/5.14/CORE -lperl
-ldl -lm -lpthread -lcrypt -L/usr/lib/python2.7/config -lpython2.7
-lpthread -ldl -lutil -lm -Xlinker -export-dynamic -Wl,-O1
-Wl,-Bsymbolic-functions  -L/usr/lib -ltcl8.5 -ldl -lpthread -lieee
-lm -lruby1.8 -lpthread -lrt -ldl -lcrypt -lm  -L/usr/lib   -- INSERT
---- INSERT --

-- 
You received this message from the "vim_dev" maillist.
Do not top-post! Type your reply below the text you are replying to.
For more information, visit http://www.vim.org/maillist.php

Raspunde prin e-mail lui