Add comments informing the caller about side effects

diff --git a/src/data/casereader.c b/src/data/casereader.c
index 98c10273b314dd4bbc4f81170e485136a828a756..9f3d5cf9dbeb25c94683a8f739218d6cb6c0ba0d 100644 (file)
--- a/src/data/casereader.c
+++ b/src/data/casereader.c
@@ -331,7 +331,7 @@ casereader_advance (struct casereader *reader, casenumber n)
 
 
 /* Copies all the cases in READER to WRITER, propagating errors
-   appropriately. */
+   appropriately. READER is destroyed by this function */
 void
 casereader_transfer (struct casereader *reader, struct casewriter *writer)
 {

diff --git a/src/math/sort.c b/src/math/sort.c
index 8719d877e096fcc9fc0d0f911d462d7bd0566725..5b82277cb7b255f25c1663b6bbc1167f8bae72f9 100644 (file)
--- a/src/math/sort.c
+++ b/src/math/sort.c
@@ -169,7 +169,9 @@ static struct casewriter_class sort_casewriter_class =
   };
 \f
 /* Reads all the cases from INPUT.  Sorts the cases according to
-   ORDERING.  Returns the sorted cases in a new casereader. */
+   ORDERING.  Returns the sorted cases in a new casereader.
+   INPUT is destroyed by this function.
+ */
 struct casereader *
 sort_execute (struct casereader *input, const struct subcase *ordering)
 {
@@ -181,7 +183,7 @@ sort_execute (struct casereader *input, const struct subcase *ordering)
 
 /* Reads all the cases from INPUT.  Sorts the cases in ascending
    order according to VARIABLE.  Returns the sorted cases in a
-   new casereader. */
+   new casereader.  INPUT is destroyed by this function. */
 struct casereader *
 sort_execute_1var (struct casereader *input, const struct variable *var)
 {