Merge topic 'doc-list-non-existent'

b573a732dc Tests: add tests to check claims in the documentation
b151db01f9 Help: mention non-existent case for list(PREPEND)
b3a249c2cb Help: clarify range for list(INSERT), mention nonexistent / empty case
b6fdcb3df0 Help: clarify description of list(INSERT)
e55f473ea9 Help: clarify that list(APPEND) on a non-existent list creates it

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !6824

1 files changed, 12 insertions, 3 deletions

diff --git a/Help/command/list.rst b/Help/command/list.rst
index 9b49cb4..33c4f80 100644
--- a/Help/command/list.rst
+++ b/Help/command/list.rst
@@ -128,7 +128,9 @@ Modification
 
   list(APPEND <list> [<element> ...])
 
-Appends elements to the list.
+Appends elements to the list. If no variable named ``<list>`` exists in the
+current scope its value is treated as empty and the elements are appended to
+that empty list.
 
 .. _FILTER:
 
@@ -150,7 +152,12 @@ For more information on regular expressions look under
 
   list(INSERT <list> <element_index> <element> [<element> ...])
 
-Inserts elements to the list to the specified location.
+Inserts elements to the list to the specified index. It is an
+error to specify an out-of-range index. Valid indexes are 0 to `N`
+where `N` is the length of the list, inclusive. An empty list
+has length 0. If no variable named ``<list>`` exists in the
+current scope its value is treated as empty and the elements are
+inserted in that empty list.
 
 .. _POP_BACK:
 
@@ -186,7 +193,9 @@ to the given variables and then remove the first `N` values from
 
 .. versionadded:: 3.15
 
-Insert elements to the 0th position in the list.
+Insert elements to the 0th position in the list. If no variable named
+``<list>`` exists in the current scope its value is treated as empty and
+the elements are prepended to that empty list.
 
 .. _REMOVE_ITEM: