ENH: completion can use different todo.sh locations and configurations.

This was previously not supported; todo_completion always used plain todo.sh from the PATH. Now it's possible to override the used executable (and configuration used through _todo_sh, set from a completion function wrapper.

Cp. http://tech.groups.yahoo.com/group/todotxt/message/4003

tests/t6080-completion-path.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+#
+
+test_description='Bash completion with different path functionality
+
+This test checks that todo_completion can use a different path to todo.sh when
+it is not accessible through PATH.
+'
+. ./test-lib.sh
+
+cat > todo.txt <<EOF
+(B) smell the +roses @outside @outdoor +shared
+notice the sunflowers +sunflowers @outside @garden +shared +landscape
+stop
+EOF
+
+mv bin/todo.sh bin/todo2.sh
+test_expect_success 'todo2.sh executable' 'todo2.sh list'
+
+# Define a second completion function that injects the different executable. In
+# real use, this would be installed via
+#   complete -F _todo2 todo2.sh
+_todo2()
+{
+    local _todo_sh='todo2.sh'
+    _todo "$@"
+}
+
+test_todo_custom_completion _todo2 'all todo2 contexts' 'todo2 list @' '@garden @outdoor @outside'
+
+
+
+# Remove the test environment's bin directory from the PATH, so that our test
+# executable must be launched with an explicit path.
+PATH=${PATH##"${PWD}/bin:"}
+test_expect_code 127 'todo2.sh executable not in PATH' 'todo2.sh'
+
+_todo2path()
+{
+    local _todo_sh='./bin/todo2.sh'
+    _todo "$@"
+}
+test_todo_custom_completion _todo2path 'all todo2 contexts' 'todo2 list @' '@garden @outdoor @outside'
+
+test_done