mergetool: move main program flow into a main() function

Make it easier to follow the program's flow by isolating all logic into functions. Isolate the main execution code path into a single unit instead of having prompt_after_failed_merge() interrupt it partyway through. The use of a main() function is borrowing a convention from C, Python, Perl, and many other languages. This helps readers more familiar with other languages understand the purpose of each function when diving into the codebase with fresh eyes. Signed-off-by: David Aguilar <[email protected]> Reviewed-by: Johannes Sixt <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
DataREPL · Oct 11, 2016 · 08221e3 · 08221e3
1 parent 8827b3a
commit 08221e3
Showing 1 changed file with 93 additions and 87 deletions.
diff --git a/git-mergetool.sh b/git-mergetool.sh
@@ -366,51 +366,6 @@ merge_file () {
 	return 0
 }
 
-prompt=$(git config --bool mergetool.prompt)
-guessed_merge_tool=false
-
-while test $# != 0
-do
-	case "$1" in
-	--tool-help=*)
-		TOOL_MODE=${1#--tool-help=}
-		show_tool_help
-		;;
-	--tool-help)
-		show_tool_help
-		;;
-	-t|--tool*)
-		case "$#,$1" in
-		*,*=*)
-			merge_tool=$(expr "z$1" : 'z-[^=]*=\(.*\)')
-			;;
-		1,*)
-			usage ;;
-		*)
-			merge_tool="$2"
-			shift ;;
-		esac
-		;;
-	-y|--no-prompt)
-		prompt=false
-		;;
-	--prompt)
-		prompt=true
-		;;
-	--)
-		shift
-		break
-		;;
-	-*)
-		usage
-		;;
-	*)
-		break
-		;;
-	esac
-	shift
-done
-
 prompt_after_failed_merge () {
 	while true
 	do
@@ -427,57 +382,108 @@ prompt_after_failed_merge () {
 	done
 }
 
-git_dir_init
-require_work_tree
+main () {
+	prompt=$(git config --bool mergetool.prompt)
+	guessed_merge_tool=false
+
+	while test $# != 0
+	do
+		case "$1" in
+		--tool-help=*)
+			TOOL_MODE=${1#--tool-help=}
+			show_tool_help
+			;;
+		--tool-help)
+			show_tool_help
+			;;
+		-t|--tool*)
+			case "$#,$1" in
+			*,*=*)
+				merge_tool=$(expr "z$1" : 'z-[^=]*=\(.*\)')
+				;;
+			1,*)
+				usage ;;
+			*)
+				merge_tool="$2"
+				shift ;;
+			esac
+			;;
+		-y|--no-prompt)
+			prompt=false
+			;;
+		--prompt)
+			prompt=true
+			;;
+		--)
+			shift
+			break
+			;;
+		-*)
+			usage
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+
+	git_dir_init
+	require_work_tree
 
-if test -z "$merge_tool"
-then
-	# Check if a merge tool has been configured
-	merge_tool=$(get_configured_merge_tool)
-	# Try to guess an appropriate merge tool if no tool has been set.
 	if test -z "$merge_tool"
 	then
-		merge_tool=$(guess_merge_tool) || exit
-		guessed_merge_tool=true
+		# Check if a merge tool has been configured
+		merge_tool=$(get_configured_merge_tool)
+		# Try to guess an appropriate merge tool if no tool has been set.
+		if test -z "$merge_tool"
+		then
+			merge_tool=$(guess_merge_tool) || exit
+			guessed_merge_tool=true
+		fi
 	fi
-fi
-merge_keep_backup="$(git config --bool mergetool.keepBackup || echo true)"
-merge_keep_temporaries="$(git config --bool mergetool.keepTemporaries || echo false)"
-
-files=
+	merge_keep_backup="$(git config --bool mergetool.keepBackup || echo true)"
+	merge_keep_temporaries="$(git config --bool mergetool.keepTemporaries || echo false)"
 
-if test $# -eq 0
-then
-	cd_to_toplevel
+	files=
 
-	if test -e "$GIT_DIR/MERGE_RR"
+	if test $# -eq 0
 	then
-		files=$(git rerere remaining)
+		cd_to_toplevel
+
+		if test -e "$GIT_DIR/MERGE_RR"
+		then
+			files=$(git rerere remaining)
+		else
+			files=$(git ls-files -u |
+				sed -e 's/^[^	]*	//' | sort -u)
+		fi
 	else
-		files=$(git ls-files -u | sed -e 's/^[^	]*	//' | sort -u)
+		files=$(git ls-files -u -- "$@" |
+			sed -e 's/^[^	]*	//' | sort -u)
 	fi
-else
-	files=$(git ls-files -u -- "$@" | sed -e 's/^[^	]*	//' | sort -u)
-fi
-
-if test -z "$files"
-then
-	echo "No files need merging"
-	exit 0
-fi
-
-printf "Merging:\n"
-printf "%s\n" "$files"
-
-rc=0
-for i in $files
-do
-	printf "\n"
-	if ! merge_file "$i"
+
+	if test -z "$files"
 	then
-		rc=1
-		prompt_after_failed_merge || exit 1
+		echo "No files need merging"
+		exit 0
 	fi
-done
 
-exit $rc
+	printf "Merging:\n"
+	printf "%s\n" "$files"
+
+	rc=0
+	for i in $files
+	do
+		printf "\n"
+		if ! merge_file "$i"
+		then
+			rc=1
+			prompt_after_failed_merge || exit 1
+		fi
+	done
+
+	exit $rc
+}
+
+main "$@"