mergetool--lib: Add Beyond Compare 3 as a tool

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Tested-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-difftool.txt

@@ -31,7 +31,7 @@ OPTIONS
 --tool=<tool>::
 	Use the diff tool specified by <tool>.
 	Valid merge tools are:
-	araxis, diffuse, emerge, ecmerge, gvimdiff, kdiff3,
+	araxis, bc3, diffuse, emerge, ecmerge, gvimdiff, kdiff3,
 	kompare, meld, opendiff, p4merge, tkdiff, vimdiff and xxdiff.
 +
 If a diff tool is not specified, 'git difftool'

Documentation/git-mergetool.txt

@@ -26,7 +26,7 @@ OPTIONS
 --tool=<tool>::
 	Use the merge resolution program specified by <tool>.
 	Valid merge tools are:
-	araxis, diffuse, ecmerge, emerge, gvimdiff, kdiff3,
+	araxis, bc3, diffuse, ecmerge, emerge, gvimdiff, kdiff3,
 	meld, opendiff, p4merge, tkdiff, tortoisemerge, vimdiff and xxdiff.
 +
 If a merge resolution program is not specified, 'git mergetool'

Documentation/merge-config.txt

@@ -34,7 +34,7 @@ merge.stat::
 merge.tool::
 	Controls which merge resolution program is used by
 	linkgit:git-mergetool[1].  Valid built-in values are: "araxis",
-	"diffuse", "ecmerge", "emerge", "gvimdiff", "kdiff3", "meld",
+	"bc3", "diffuse", "ecmerge", "emerge", "gvimdiff", "kdiff3", "meld",
 	"opendiff", "p4merge", "tkdiff", "tortoisemerge", "vimdiff"
 	and "xxdiff".  Any other value is treated is custom merge tool
 	and there must be a corresponding mergetool.<tool>.cmd option.

contrib/completion/git-completion.bash

@@ -1358,7 +1358,7 @@ _git_diff ()
 }
 
 __git_mergetools_common="diffuse ecmerge emerge kdiff3 meld opendiff
-			tkdiff vimdiff gvimdiff xxdiff araxis p4merge
+			tkdiff vimdiff gvimdiff xxdiff araxis p4merge bc3
 "
 
 _git_difftool ()

git-mergetool--lib.sh

@@ -13,6 +13,9 @@ translate_merge_tool_path () {
 	araxis)
 		echo compare
 		;;
+	bc3)
+		echo bcompare
+		;;
 	emerge)
 		echo emacs
 		;;
@@ -46,7 +49,7 @@ check_unchanged () {
 
 valid_tool () {
 	case "$1" in
-	araxis | diffuse | ecmerge | emerge | gvimdiff | gvimdiff2 | \
+	araxis | bc3 | diffuse | ecmerge | emerge | gvimdiff | gvimdiff2 | \
 	kdiff3 | meld | opendiff | p4merge | tkdiff | vimdiff | vimdiff2 | xxdiff)
 		;; # happy
 	kompare)
@@ -106,6 +109,21 @@ run_merge_tool () {
 				>/dev/null 2>&1
 		fi
 		;;
+	bc3)
+		if merge_mode; then
+			touch "$BACKUP"
+			if $base_present; then
+				"$merge_tool_path" "$LOCAL" "$REMOTE" "$BASE" \
+					-mergeoutput="$MERGED"
+			else
+				"$merge_tool_path" "$LOCAL" "$REMOTE" \
+					-mergeoutput="$MERGED"
+			fi
+			check_unchanged
+		else
+			"$merge_tool_path" "$LOCAL" "$REMOTE"
+		fi
+		;;
 	diffuse)
 		if merge_mode; then
 			touch "$BACKUP"
@@ -342,7 +360,7 @@ guess_merge_tool () {
 		else
 			tools="opendiff kdiff3 tkdiff xxdiff meld $tools"
 		fi
-		tools="$tools gvimdiff diffuse ecmerge p4merge araxis"
+		tools="$tools gvimdiff diffuse ecmerge p4merge araxis bc3"
 	fi
 	case "${VISUAL:-$EDITOR}" in
 	*vim*)