mergetool--lib: improve the help text in guess_merge_tool()

This code path is only activated when the user does not have a valid
configured tool.  Add a message to guide new users towards configuring a
default tool.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
index 2a67383081cae8e33702fdb70db51fb1d1db87ba..7edc27f92c462774c37f65904cb17a64d86eb6e3 100644 (file)
--- a/git-mergetool--lib.sh
+++ b/git-mergetool--lib.sh
@@ -240,7 +240,13 @@ show_tool_help () {
 
 guess_merge_tool () {
        list_merge_tool_candidates
-       echo >&2 "merge tool candidates: $tools"
+       cat >&2 <<-EOF
+
+       This message is displayed because '$TOOL_MODE.tool' is not configured.
+       See 'git ${TOOL_MODE}tool --tool-help' or 'git help config' for more details.
+       'git ${TOOL_MODE}tool' will now attempt to use one of the following tools:
+       $tools
+       EOF
 
        # Loop over each candidate and stop when a valid merge tool is found.
        for i in $tools