completion: don't modify the $cur variable in completion functions

Since v1.7.4-rc0~11^2~2 (bash: get --pretty=m<tab> completion to work
with bash v4, 2010-12-02) we use _get_comp_words_by_ref() to access
completion-related variables, and the $cur variable holds the word
containing the current cursor position in all completion functions.
This $cur variable is left unchanged in most completion functions;
there are only four functions modifying its value, namely __gitcomp(),
__git_complete_revlist_file(), __git_complete_remote_or_refspec(), and
_git_config().

If this variable were never modified, then it would allow us a nice
optimisation and cleanup.  Therefore, this patch assigns $cur to an
other local variable and uses that for later modifications in those
four functions.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 9150ea60267913dd17e749afdf2bca348646a165..2ca91a3cc3140bdefeeb9afd0e6412e198a5b4f3 100755 (executable)
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -491,10 +491,12 @@ __gitcomp ()
 {
        local cur
        _get_comp_words_by_ref -n =: cur
+       local cur_="$cur"
+
        if [ $# -gt 2 ]; then
-               cur="$3"
+               cur_="$3"
        fi
-       case "$cur" in
+       case "$cur_" in
        --*=)
                COMPREPLY=()
                ;;
@@ -502,7 +504,7 @@ __gitcomp ()
                local IFS=$'\n'
                COMPREPLY=($(compgen -P "${2-}" \
                        -W "$(__gitcomp_1 "${1-}" "${4-}")" \
-                       -- "$cur"))
+                       -- "$cur_"))
                ;;
        esac
 }
@@ -668,17 +670,18 @@ __git_complete_revlist_file ()
 {
        local pfx ls ref cur
        _get_comp_words_by_ref -n =: cur
-       case "$cur" in
+       local cur_="$cur"
+       case "$cur_" in
        *..?*:*)
                return
                ;;
        ?*:*)
-               ref="${cur%%:*}"
-               cur="${cur#*:}"
-               case "$cur" in
+               ref="${cur_%%:*}"
+               cur_="${cur_#*:}"
+               case "$cur_" in
                ?*/*)
-                       pfx="${cur%/*}"
-                       cur="${cur##*/}"
+                       pfx="${cur_%/*}"
+                       cur_="${cur_##*/}"
                        ls="$ref:$pfx"
                        pfx="$pfx/"
                        ;;
@@ -708,17 +711,17 @@ __git_complete_revlist_file ()
                                           s,$,/,
                                       }
                                       s/^.*    //')" \
-                       -- "$cur"))
+                       -- "$cur_"))
                ;;
        *...*)
-               pfx="${cur%...*}..."
-               cur="${cur#*...}"
-               __gitcomp "$(__git_refs)" "$pfx" "$cur"
+               pfx="${cur_%...*}..."
+               cur_="${cur_#*...}"
+               __gitcomp "$(__git_refs)" "$pfx" "$cur_"
                ;;
        *..*)
-               pfx="${cur%..*}.."
-               cur="${cur#*..}"
-               __gitcomp "$(__git_refs)" "$pfx" "$cur"
+               pfx="${cur_%..*}.."
+               cur_="${cur_#*..}"
+               __gitcomp "$(__git_refs)" "$pfx" "$cur_"
                ;;
        *)
                __gitcomp "$(__git_refs)"
@@ -741,7 +744,7 @@ __git_complete_remote_or_refspec ()
 {
        local cur words cword
        _get_comp_words_by_ref -n =: cur words cword
-       local cmd="${words[1]}"
+       local cur_="$cur" cmd="${words[1]}"
        local i c=2 remote="" pfx="" lhs=1 no_complete_refspec=0
        while [ $c -lt $cword ]; do
                i="${words[c]}"
@@ -771,40 +774,40 @@ __git_complete_remote_or_refspec ()
                return
        fi
        [ "$remote" = "." ] && remote=
-       case "$cur" in
+       case "$cur_" in
        *:*)
                case "$COMP_WORDBREAKS" in
                *:*) : great ;;
-               *)   pfx="${cur%%:*}:" ;;
+               *)   pfx="${cur_%%:*}:" ;;
                esac
-               cur="${cur#*:}"
+               cur_="${cur_#*:}"
                lhs=0
                ;;
        +*)
                pfx="+"
-               cur="${cur#+}"
+               cur_="${cur_#+}"
                ;;
        esac
        case "$cmd" in
        fetch)
                if [ $lhs = 1 ]; then
-                       __gitcomp "$(__git_refs2 "$remote")" "$pfx" "$cur"
+                       __gitcomp "$(__git_refs2 "$remote")" "$pfx" "$cur_"
                else
-                       __gitcomp "$(__git_refs)" "$pfx" "$cur"
+                       __gitcomp "$(__git_refs)" "$pfx" "$cur_"
                fi
                ;;
        pull)
                if [ $lhs = 1 ]; then
-                       __gitcomp "$(__git_refs "$remote")" "$pfx" "$cur"
+                       __gitcomp "$(__git_refs "$remote")" "$pfx" "$cur_"
                else
-                       __gitcomp "$(__git_refs)" "$pfx" "$cur"
+                       __gitcomp "$(__git_refs)" "$pfx" "$cur_"
                fi
                ;;
        push)
                if [ $lhs = 1 ]; then
-                       __gitcomp "$(__git_refs)" "$pfx" "$cur"
+                       __gitcomp "$(__git_refs)" "$pfx" "$cur_"
                else
-                       __gitcomp "$(__git_refs "$remote")" "$pfx" "$cur"
+                       __gitcomp "$(__git_refs "$remote")" "$pfx" "$cur_"
                fi
                ;;
        esac
@@ -2012,70 +2015,60 @@ _git_config ()
                return
                ;;
        branch.*.*)
-               local pfx="${cur%.*}."
-               cur="${cur##*.}"
-               __gitcomp "remote merge mergeoptions rebase" "$pfx" "$cur"
+               local pfx="${cur%.*}." cur_="${cur##*.}"
+               __gitcomp "remote merge mergeoptions rebase" "$pfx" "$cur_"
                return
                ;;
        branch.*)
-               local pfx="${cur%.*}."
-               cur="${cur#*.}"
-               __gitcomp "$(__git_heads)" "$pfx" "$cur" "."
+               local pfx="${cur%.*}." cur_="${cur#*.}"
+               __gitcomp "$(__git_heads)" "$pfx" "$cur_" "."
                return
                ;;
        guitool.*.*)
-               local pfx="${cur%.*}."
-               cur="${cur##*.}"
+               local pfx="${cur%.*}." cur_="${cur##*.}"
                __gitcomp "
                        argprompt cmd confirm needsfile noconsole norescan
                        prompt revprompt revunmerged title
-                       " "$pfx" "$cur"
+                       " "$pfx" "$cur_"
                return
                ;;
        difftool.*.*)
-               local pfx="${cur%.*}."
-               cur="${cur##*.}"
-               __gitcomp "cmd path" "$pfx" "$cur"
+               local pfx="${cur%.*}." cur_="${cur##*.}"
+               __gitcomp "cmd path" "$pfx" "$cur_"
                return
                ;;
        man.*.*)
-               local pfx="${cur%.*}."
-               cur="${cur##*.}"
-               __gitcomp "cmd path" "$pfx" "$cur"
+               local pfx="${cur%.*}." cur_="${cur##*.}"
+               __gitcomp "cmd path" "$pfx" "$cur_"
                return
                ;;
        mergetool.*.*)
-               local pfx="${cur%.*}."
-               cur="${cur##*.}"
-               __gitcomp "cmd path trustExitCode" "$pfx" "$cur"
+               local pfx="${cur%.*}." cur_="${cur##*.}"
+               __gitcomp "cmd path trustExitCode" "$pfx" "$cur_"
                return
                ;;
        pager.*)
-               local pfx="${cur%.*}."
-               cur="${cur#*.}"
+               local pfx="${cur%.*}." cur_="${cur#*.}"
                __git_compute_all_commands
-               __gitcomp "$__git_all_commands" "$pfx" "$cur"
+               __gitcomp "$__git_all_commands" "$pfx" "$cur_"
                return
                ;;
        remote.*.*)
-               local pfx="${cur%.*}."
-               cur="${cur##*.}"
+               local pfx="${cur%.*}." cur_="${cur##*.}"
                __gitcomp "
                        url proxy fetch push mirror skipDefaultUpdate
                        receivepack uploadpack tagopt pushurl
-                       " "$pfx" "$cur"
+                       " "$pfx" "$cur_"
                return
                ;;
        remote.*)
-               local pfx="${cur%.*}."
-               cur="${cur#*.}"
-               __gitcomp "$(__git_remotes)" "$pfx" "$cur" "."
+               local pfx="${cur%.*}." cur_="${cur#*.}"
+               __gitcomp "$(__git_remotes)" "$pfx" "$cur_" "."
                return
                ;;
        url.*.*)
-               local pfx="${cur%.*}."
-               cur="${cur##*.}"
-               __gitcomp "insteadOf pushInsteadOf" "$pfx" "$cur"
+               local pfx="${cur%.*}." cur_="${cur##*.}"
+               __gitcomp "insteadOf pushInsteadOf" "$pfx" "$cur_"
                return
                ;;
        esac