Merge branch 'rs/work-around-grep-opt-insanity' into maint

* rs/work-around-grep-opt-insanity:
  Protect scripted Porcelains from GREP_OPTIONS insanity
  mergetool--lib: simplify guess_merge_tool()

Author: gitster

git-am.sh

@@ -205,7 +205,7 @@ check_patch_format () {
 			# and see if it looks like that they all begin with the
 			# header field names...
 			sed -n -e '/^$/q' -e '/^[ 	]/d' -e p "$1" |
-			LC_ALL=C egrep -v '^[!-9;-~]+:' >/dev/null ||
+			sane_egrep -v '^[!-9;-~]+:' >/dev/null ||
 			patch_format=mbox
 		fi
 	} < "$1" || clean_abort
@@ -561,7 +561,7 @@ do
 			stop_here $this
 
 		# skip pine's internal folder data
-		grep '^Author: Mail System Internal Data$' \
+		sane_grep '^Author: Mail System Internal Data$' \
 			<"$dotest"/info >/dev/null &&
 			go_next && continue
 

git-bisect.sh

@@ -393,7 +393,7 @@ bisect_run () {
 
       cat "$GIT_DIR/BISECT_RUN"
 
-      if grep "first bad commit could be any of" "$GIT_DIR/BISECT_RUN" \
+      if sane_grep "first bad commit could be any of" "$GIT_DIR/BISECT_RUN" \
 		> /dev/null; then
 	  echo >&2 "bisect run cannot continue any more"
 	  exit $res
@@ -405,7 +405,7 @@ bisect_run () {
 	  exit $res
       fi
 
-      if grep "is the first bad commit" "$GIT_DIR/BISECT_RUN" > /dev/null; then
+      if sane_grep "is the first bad commit" "$GIT_DIR/BISECT_RUN" > /dev/null; then
 	  echo "bisect run success"
 	  exit 0;
       fi

git-filter-branch.sh

@@ -457,7 +457,7 @@ if [ "$filter_tag_name" ]; then
 				git mktag) ||
 				die "Could not create new tag object for $ref"
 			if git cat-file tag "$ref" | \
-			   grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
+			   sane_grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
 			then
 				warn "gpg signature stripped from tag object $sha1t"
 			fi

git-instaweb.sh

@@ -41,7 +41,7 @@ resolve_full_httpd () {
 	case "$httpd" in
 	*apache2*|*lighttpd*)
 		# ensure that the apache2/lighttpd command ends with "-f"
-		if ! echo "$httpd" | grep -- '-f *$' >/dev/null 2>&1
+		if ! echo "$httpd" | sane_grep -- '-f *$' >/dev/null 2>&1
 		then
 			httpd="$httpd -f"
 		fi
@@ -302,8 +302,8 @@ EOF
 
 	# check to see if Dennis Stosberg's mod_perl compatibility patch
 	# (<[email protected]>) has been applied
-	if test -f "$module_path/mod_perl.so" && grep 'MOD_PERL' \
-				"$GIT_DIR/gitweb/gitweb.cgi" >/dev/null
+	if test -f "$module_path/mod_perl.so" &&
+	   sane_grep 'MOD_PERL' "$GIT_DIR/gitweb/gitweb.cgi" >/dev/null
 	then
 		# favor mod_perl if available
 		cat >> "$conf" <<EOF
@@ -321,7 +321,7 @@ EOF
 		# plain-old CGI
 		resolve_full_httpd
 		list_mods=$(echo "$full_httpd" | sed "s/-f$/-l/")
-		$list_mods | grep 'mod_cgi\.c' >/dev/null 2>&1 || \
+		$list_mods | sane_grep 'mod_cgi\.c' >/dev/null 2>&1 || \
 		echo "LoadModule cgi_module $module_path/mod_cgi.so" >> "$conf"
 		cat >> "$conf" <<EOF
 AddHandler cgi-script .cgi

git-mergetool--lib.sh

@@ -325,15 +325,14 @@ guess_merge_tool () {
 		fi
 		tools="$tools gvimdiff diffuse ecmerge araxis"
 	fi
-	if echo "${VISUAL:-$EDITOR}" | grep emacs > /dev/null 2>&1; then
-		# $EDITOR is emacs so add emerge as a candidate
-		tools="$tools emerge vimdiff"
-	elif echo "${VISUAL:-$EDITOR}" | grep vim > /dev/null 2>&1; then
-		# $EDITOR is vim so add vimdiff as a candidate
+	case "${VISUAL:-$EDITOR}" in
+	*vim*)
 		tools="$tools vimdiff emerge"
-	else
+		;;
+	*)
 		tools="$tools emerge vimdiff"
-	fi
+		;;
+	esac
 	echo >&2 "merge tool candidates: $tools"
 
 	# Loop over each candidate and stop when a valid merge tool is found.

git-rebase--interactive.sh

@@ -106,8 +106,8 @@ mark_action_done () {
 	sed -e 1q < "$TODO" >> "$DONE"
 	sed -e 1d < "$TODO" >> "$TODO".new
 	mv -f "$TODO".new "$TODO"
-	count=$(grep -c '^[^#]' < "$DONE")
-	total=$(($count+$(grep -c '^[^#]' < "$TODO")))
+	count=$(sane_grep -c '^[^#]' < "$DONE")
+	total=$(($count+$(sane_grep -c '^[^#]' < "$TODO")))
 	if test "$last_count" != "$count"
 	then
 		last_count=$count
@@ -147,7 +147,7 @@ die_abort () {
 }
 
 has_action () {
-	grep '^[^#]' "$1" >/dev/null
+	sane_grep '^[^#]' "$1" >/dev/null
 }
 
 pick_one () {
@@ -736,15 +736,15 @@ first and then run 'git rebase --continue' again."
 			git rev-list $REVISIONS |
 			while read rev
 			do
-				if test -f "$REWRITTEN"/$rev -a "$(grep "$rev" "$DOTEST"/not-cherry-picks)" = ""
+				if test -f "$REWRITTEN"/$rev -a "$(sane_grep "$rev" "$DOTEST"/not-cherry-picks)" = ""
 				then
 					# Use -f2 because if rev-list is telling us this commit is
 					# not worthwhile, we don't want to track its multiple heads,
 					# just the history of its first-parent for others that will
 					# be rebasing on top of it
 					git rev-list --parents -1 $rev | cut -d' ' -s -f2 > "$DROPPED"/$rev
 					short=$(git rev-list -1 --abbrev-commit --abbrev=7 $rev)
-					grep -v "^[a-z][a-z]* $short" <"$TODO" > "${TODO}2" ; mv "${TODO}2" "$TODO"
+					sane_grep -v "^[a-z][a-z]* $short" <"$TODO" > "${TODO}2" ; mv "${TODO}2" "$TODO"
 					rm "$REWRITTEN"/$rev
 				fi
 			done

git-rebase.sh

@@ -467,7 +467,7 @@ orig_head=$branch
 mb=$(git merge-base "$onto" "$branch")
 if test "$upstream" = "$onto" && test "$mb" = "$onto" &&
 	# linear history?
-	! (git rev-list --parents "$onto".."$branch" | grep " .* ") > /dev/null
+	! (git rev-list --parents "$onto".."$branch" | sane_grep " .* ") > /dev/null
 then
 	if test -z "$force_rebase"
 	then

git-sh-setup.sh

@@ -114,6 +114,14 @@ git_editor() {
 	eval "${GIT_EDITOR:=vi}" '"$@"'
 }
 
+sane_grep () {
+	GREP_OPTIONS= LC_ALL=C grep "$@"
+}
+
+sane_egrep () {
+	GREP_OPTIONS= LC_ALL=C egrep "$@"
+}
+
 is_bare_repository () {
 	git rev-parse --is-bare-repository
 }

git-submodule.sh

@@ -57,7 +57,7 @@ resolve_relative_url ()
 #
 module_list()
 {
-	git ls-files --error-unmatch --stage -- "$@" | grep '^160000 '
+	git ls-files --error-unmatch --stage -- "$@" | sane_grep '^160000 '
 }
 
 #
@@ -567,7 +567,7 @@ cmd_summary() {
 	cd_to_toplevel
 	# Get modified modules cared by user
 	modules=$(git $diff_cmd $cached --raw $head -- "$@" |
-		egrep '^:([0-7]* )?160000' |
+		sane_egrep '^:([0-7]* )?160000' |
 		while read mod_src mod_dst sha1_src sha1_dst status name
 		do
 			# Always show modules deleted or type-changed (blob<->module)
@@ -581,7 +581,7 @@ cmd_summary() {
 	test -z "$modules" && return
 
 	git $diff_cmd $cached --raw $head -- $modules |
-	egrep '^:([0-7]* )?160000' |
+	sane_egrep '^:([0-7]* )?160000' |
 	cut -c2- |
 	while read mod_src mod_dst sha1_src sha1_dst status name
 	do