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[PATCH] manual: Correct guarantee about pointers compared by qsort()


C99, C11, POSIX, and the glibc implementation do guarantee that the
pointers passed to the qsort comparison function lie within the array.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
---
 manual/search.texi | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/manual/search.texi b/manual/search.texi
index 8aff574..9ebcb68 100644
--- a/manual/search.texi
+++ b/manual/search.texi
@@ -180,10 +180,12 @@ This can make a difference when the comparison considers only part of
 the elements.  Two elements with the same sort key may differ in other
 respects.
 
-The addresses passed to the comparison function need not correspond with
-the original location of the objects, and need not even lie within the
-original array.  The only way to perform a stable sort with @var{qsort}
-is to first augment the objects with a monotonic counter of some kind.
+Although the object addresses passed to the comparison function lie
+within the array, they need not correspond with the original locations
+of those objects, because the sorting algorithm may swap around
+objects in the array before making some comparisons.  The only way to
+perform a stable sort with @var{qsort} is to first augment the objects
+with a monotonic counter of some kind.
 
 Here is a simple example of sorting an array of doubles in numerical
 order, using the comparison function defined above (@pxref{Comparison
-- 
2.2.0


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