Add tests for "git describe --long".

* Move test logic to scm-update.sh scripts.
    * Check for "git describe --long".

tests/jobs/git-update.sh

@@ -1,25 +1,49 @@
 #! /bin/sh
+# This script is used both by git & deepgit checks.
 
-cd "$1"
-STATE_FILE=.state
+repo=git-repo
+STATE_FILE=$(pwd)/.git-state
 if test -e $STATE_FILE; then
     state=$(cat $STATE_FILE)
+    test $state -gt 3 && state=0
 else
     state=0;
 fi
 
 case $state in
-    (0)
-    echo "Add new file."
-    touch git-file-2
-    git add git-file-2 >&2
-    git commit -m "add git file 2" git-file-2 >&2
+    (0) echo "::Create repo. -- continue -- updated::"
+    git init $repo
+    cd $repo
+    touch foo
+    git add foo
+    git commit -m "Add foo"
+    git tag -a -m "First Tag." tag0
+    git checkout -b master HEAD
     ;;
-    (1)
-    echo "Rewrite commit."
-    echo 1 > git-file-2
-    git add git-file-2 >&2
-    git commit --amend -m "add git file 2" git-file-2 >&2
+    (1) echo "::Create new commit. -- continue -- updated::"
+    cd $repo
+    # Increase depth to make sure the tag is not fetched by default.
+    echo 0 > foo
+    git add foo
+    git commit -m "Increase depth 0"
+    echo 1 > foo
+    git add foo
+    git commit -m "Increase depth 1"
+    echo 2 > foo
+    git add foo
+    git commit -m "Increase depth 2"
+    echo 0 > bar
+    git add bar
+    git commit -m "Add bar with 0"
+    ;;
+    (2) echo "::Amend commit. (push -f) -- continue -- updated::"
+    cd $repo
+    echo 1 > bar
+    git add bar
+    git commit --amend -m "Add bar with 1"
+    ;;
+    (*) echo "::End. -- stop -- nothing::"
+    rm -rf $repo
     ;;
 esac