patch 8.0.1406: difficult to track changes to a quickfix listv8.0.1406

Problem:    Difficult to track changes to a quickfix list.
Solution:   Add a "changedtick" value. (Yegappan Lakshmanan, closes #2460)

1 files changed, 8 insertions, 0 deletions

diff --git a/runtime/doc/quickfix.txt b/runtime/doc/quickfix.txt
index 29752db8fb..75ff404db2 100644
--- a/runtime/doc/quickfix.txt
+++ b/runtime/doc/quickfix.txt
@@ -64,6 +64,14 @@ When a window with a location list is split, the new window gets a copy of the
 location list.  When there are no longer any references to a location list,
 the location list is destroyed.
 
+						*quickfix-changedtick*
+Every quickfix and location list has a read-only changedtick variable that
+tracks the total number of changes made to the list.  Every time the quickfix
+list is modified, this count is incremented. This can be used to perform an
+action only when the list has changed.  The getqflist() and getloclist()
+functions can be used to query the current value of changedtick.  You cannot
+change the changedtick variable.
+
 The following quickfix commands can be used.  The location list commands are
 similar to the quickfix commands, replacing the 'c' prefix in the quickfix
 command with 'l'.