#!/bin/sh
# git-difftool--helper is a GIT_EXTERNAL_DIFF-compatible diff tool launcher.
# This script is typically launched by using the 'git difftool'
# convenience command.
#
# Copyright (c) 2009, 2010 David Aguilar

global TOOL_MODE := 'diff'
source git-mergetool--lib

# difftool.prompt controls the default prompt/no-prompt behavior
# and is overridden with $GIT_DIFFTOOL*_PROMPT.
proc should_prompt {
	global prompt_merge := $[git config --bool mergetool.prompt || echo true]
	global prompt := $[git config --bool difftool.prompt || echo $prompt_merge]
	if test $prompt = true
	{
		test -z $GIT_DIFFTOOL_NO_PROMPT
	} else {
		test -n $GIT_DIFFTOOL_PROMPT
	}
}

# Indicates that --extcmd=... was specified
proc use_ext_cmd {
	test -n $GIT_DIFFTOOL_EXTCMD
}

proc launch_merge_tool {
	# Merged is the filename as it appears in the work tree
	# Local is the contents of a/filename
	# Remote is the contents of b/filename
	# Custom merge tool commands might use $BASE so we provide it
	global MERGED := $1
	global LOCAL := $2
	global REMOTE := $3
	global BASE := $1

	# $LOCAL and $REMOTE are temporary files so prompt
	# the user with the real $MERGED name before launching $merge_tool.
	if should_prompt
	{
		printf "\nViewing (%s/%s): '%s'\n" $GIT_DIFF_PATH_COUNTER \
			$GIT_DIFF_PATH_TOTAL $MERGED
		if use_ext_cmd
		{
			printf "Launch '%s' [Y/n]? " \
				$GIT_DIFFTOOL_EXTCMD
		} else {
			printf "Launch '%s' [Y/n]? " $merge_tool
		}
		read ans || return
		if test $ans = n
		{
			return
		}
	}

	if use_ext_cmd
	{
		export BASE
		eval $GIT_DIFFTOOL_EXTCMD '"$LOCAL"' '"$REMOTE"'
	} else {
		run_merge_tool $merge_tool
	}
}

if ! use_ext_cmd
{
	if test -n $GIT_DIFF_TOOL
	{
		global merge_tool := $GIT_DIFF_TOOL
	} else {
		global merge_tool := $[get_merge_tool] || exit
	}
}

if test -n $GIT_DIFFTOOL_DIRDIFF
{
	global LOCAL := $1
	global REMOTE := $2
	run_merge_tool $merge_tool false
} else {
	# Launch the merge tool on each path provided by 'git diff'
	while test $# -gt 6
	{
		launch_merge_tool $1 $2 $5
		global status := $Status
		if test $status -ge 126
		{
			# Command not found (127), not executable (126) or
			# exited via a signal (>= 128).
			exit $status
		}

		if test $status != 0 &&
			test $GIT_DIFFTOOL_TRUST_EXIT_CODE = true
		{
			exit $status
		}
		shift 7
	}
}

exit 0
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      spids: [19]
    )
    (C {(.)} {(git-mergetool--lib)})
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                                  (C {(git)} {(config)} {(--bool)} {(mergetool.prompt)})
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                                op_id: Op_DPipe
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                        left_token: <Left_CommandSub "$(">
                        spids: [42 56]
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                      (CommandSubPart
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                            children: [
                              (AndOr
                                children: [
                                  (C {(git)} {(config)} {(--bool)} {(difftool.prompt)})
                                  (C {(echo)} {($ VSub_Name "$prompt_merge")})
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                                op_id: Op_DPipe
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                            ]
                          )
                        left_token: <Left_CommandSub "$(">
                        spids: [60 74]
                      )
                    }
                  spids: [59]
                )
              ]
              spids: [59]
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            (If
              arms: [
                (if_arm
                  cond: [(C {(test)} {(DQ ($ VSub_Name "$prompt"))} {(Lit_Other "=")} {(true)})]
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      spids: [33 37]
    )
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      name: use_ext_cmd
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        (BraceGroup
          children: [(C {(test)} {(-n)} {(DQ ($ VSub_Name "$GIT_DIFFTOOL_EXTCMD"))})]
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        )
      spids: [122 126]
    )
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            (Assignment
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                (assign_pair
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                  op: Equal
                  rhs: {(DQ ($ VSub_Number "$1"))}
                  spids: [165]
                )
              ]
              spids: [165]
            )
            (Assignment
              keyword: Assign_None
              pairs: [
                (assign_pair
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                  spids: [171]
                )
              ]
              spids: [171]
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                  spids: [177]
                )
              ]
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            )
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                        )
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                            )
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                      {(SQ <"\"$REMOTE\"">)}
                    )
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                  spids: [-1 307]
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              ]
              else_action: [(C {(run_merge_tool)} {(DQ ($ VSub_Name "$merge_tool"))})]
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                          spids: [375]
                        )
                      ]
                      spids: [375]
                    )
                    (C {(exit)})
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                )
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            )
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                )
              ]
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            (C {(run_merge_tool)} {(DQ ($ VSub_Name "$merge_tool"))} {(false)})
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          cond: [(C {(test)} {($ VSub_Pound "$#")} {(-gt)} {(6)})]
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                  {(DQ ($ VSub_Number "$5"))}
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                  pairs: [
                    (assign_pair
                      lhs: (LhsName name:status)
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                      action: [(C {(exit)} {($ VSub_Name "$status")})]
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            )
        )
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    )
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  ]
)