[PATCH] Add 'shelltools': diff tool detection (try to find GNU diff)

[David Champion]

# HG changeset patch
# User David Champion <dgc at uchicago.edu>
# Date 1246847552 18000
# Node ID b662b90acf147e5d264a083ed6302b3fc6ea82c3
# Parent  95046688f80fbe481241ed3affeed205ce378b7e
Add 'shelltools': diff tool detection (try to find GNU diff).

diff -r 95046688f80f -r b662b90acf14 tests/shelltools
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/shelltools	Sun Jul 05 21:32:32 2009 -0500
@@ -0,0 +1,9 @@
+#!/bin/sh
+#
+# Detect some shell programs.  This file is sourced from other shells,
+# so it should do nothing to irreversibly affect the current process.
+#
+
+# Detect and use GNU diff as diff, if available as 'gdiff'.
+_diff=`gdiff >/dev/null 2>&1 && echo gdiff || which diff`
+diff () { "$_diff" "$@"; }
diff -r 95046688f80f -r b662b90acf14 tests/test-command-template
--- a/tests/test-command-template	Sun Jul 05 18:52:55 2009 -0400
+++ b/tests/test-command-template	Sun Jul 05 21:32:32 2009 -0500
@@ -1,5 +1,7 @@
 #!/bin/sh
 
+. "$TESTDIR/shelltools"
+
 hg init a
 cd a
 echo a > a
diff -r 95046688f80f -r b662b90acf14 tests/test-highlight
--- a/tests/test-highlight	Sun Jul 05 18:52:55 2009 -0400
+++ b/tests/test-highlight	Sun Jul 05 21:32:32 2009 -0500
@@ -2,6 +2,8 @@
 
 "$TESTDIR/hghave" pygments || exit 80
 
+. "$TESTDIR/shelltools"
+
 cat <<EOF >> $HGRCPATH
 [extensions]
 hgext.highlight =