[postgis-tickets] r16864 - Fix undefined behaviour in SADFWrite

[Raul]

Author: algunenano
Date: 2018-10-02 02:44:15 -0700 (Tue, 02 Oct 2018)
New Revision: 16864

Modified:
   branches/2.4/NEWS
   branches/2.4/loader/safileio.c
Log:
Fix undefined behaviour in SADFWrite

References #4189


Modified: branches/2.4/NEWS
===================================================================
--- branches/2.4/NEWS	2018-10-02 09:38:48 UTC (rev 16863)
+++ branches/2.4/NEWS	2018-10-02 09:44:15 UTC (rev 16864)
@@ -5,6 +5,7 @@
   - #4160, Use qualified names in topology extension install (Raúl Marín)
   - #4181, St_AsMVTGeom: Avoid type changes due to validation (Raúl Marín)
   - #4183, St_AsMVTGeom: Drop invalid geometries after simplification (Raúl Marín)
+  - #4189, Fix undefined behaviour in SADFWrite (Raúl Marín)
 
 
 PostGIS 2.4.5

Modified: branches/2.4/loader/safileio.c
===================================================================
--- branches/2.4/loader/safileio.c	2018-10-02 09:38:48 UTC (rev 16863)
+++ branches/2.4/loader/safileio.c	2018-10-02 09:44:15 UTC (rev 16864)
@@ -115,8 +115,9 @@
 SAOffset SADFWrite( void *p, SAOffset size, SAOffset nmemb, SAFile file )
 
 {
-    return (SAOffset) fwrite( p, (size_t) size, (size_t) nmemb,
-                              (FILE *) file );
+	if (!nmemb || !p) return 0;
+	return (SAOffset) fwrite( p, (size_t) size, (size_t) nmemb,
+				(FILE *) file );
 }
 
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