[PATCH v2 2/4] mergetool--lib: Improve the help text in guess_merge_tool()

[David Aguilar <davvid@gmail.com>]

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>
---
This now uses a cat << here-doc.

 git-mergetool--lib.sh | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
index 9a5aae9..db3eb58 100644
--- a/git-mergetool--lib.sh
+++ b/git-mergetool--lib.sh
@@ -240,8 +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
 	do
-- 
1.8.0.13.g3ff16bb