[PATCH 1/1] contrib/git-jump/git-jump: support alias expansion

[Taylor Blau <me@ttaylorr.com>]

When a caller of 'git-jump' has, say, the alias 'di' assigned to 'diff',
it can be cumbersome to remember to type 'git jump diff' instead of the
shorthand '... di' that they are used to.

Let's teach 'git-jump' to expand these aliases before calling the
mode-specific subroutine. Do so by fetching the configuration value of
'alias.$1', defaulting to "$1" in the case that no alias is set.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 contrib/git-jump/README   | 4 ++++
 contrib/git-jump/git-jump | 4 +++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/contrib/git-jump/README b/contrib/git-jump/README
index 2f618a7f97..9e59990ba0 100644
--- a/contrib/git-jump/README
+++ b/contrib/git-jump/README
@@ -74,6 +74,10 @@ git jump grep -i foo_bar
 
 # use the silver searcher for git jump grep
 git config jump.grepCmd "ag --column"
+
+# jump to changes via an alias of 'git diff', assuming you have set
+# `git config alias.diff di`
+git jump di
 --------------------------------------------------
 
 
diff --git a/contrib/git-jump/git-jump b/contrib/git-jump/git-jump
index 931b0fe3a9..15e129b350 100755
--- a/contrib/git-jump/git-jump
+++ b/contrib/git-jump/git-jump
@@ -15,6 +15,8 @@ grep: elements are grep hits. Arguments are given to git grep or, if
       configured, to the command in `jump.grepCmd`.
 
 ws: elements are whitespace errors. Arguments are given to diff --check.
+
+Aliases of any of the above are expanded automatically.
 EOF
 }
 
@@ -68,7 +70,7 @@ if test $# -lt 1; then
 	usage >&2
 	exit 1
 fi
-mode=$1; shift
+mode="$(git config --default "$1" --get -- "alias.$1")"; shift
 
 trap 'rm -f "$tmp"' 0 1 2 3 15
 tmp=`mktemp -t git-jump.XXXXXX` || exit 1
-- 
2.22.0