Update PQfree() documentation to be clearer, backpatch to 8.2.X.

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 5b8ef438b36995ff9ca0409e449633fc5d128b79..a7be065ec67d0cf6a240e620aed2afa7e5f59a2d 100644 (file)
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1,4 +1,4 @@
-
+
 
  
   <application>libpq</application> - C Library
@@ -2617,9 +2617,13 @@ void PQfreemem(void *ptr);
    PQescapeBytea,
    PQunescapeBytea,
    and PQnotifies.
-   It is needed by Microsoft Windows, which cannot free memory across
-   DLLs, unless multithreaded DLLs (/MD in VC6) are used.
-   On other platforms, this function is the same as the standard library function free().
+   It is particularly important that this function, rather than
+   free(), be used on Microsoft Windows.  This is because
+   allocating memory in a DLL and releasing it in the application works
+   only if multithreaded/single-threaded, release/debug, and static/dynamic
+   flags are the same for the DLL and the application.  On non-Microsoft
+   Windows platforms, this function is the same as the standard library
+   function free().