loadsave: check for errors when using temp file

jbms · jbms · commit 2be955a0ef3e · 2017-07-31T09:02:42.000-07:00
Previously, the return value of fwrite and fclose were not properly checked, leading to possible silent truncation of the data if writing failed, e.g. due to lack of disk space. Fixes issue opencv#9251.
diff --git a/modules/imgcodecs/src/loadsave.cpp b/modules/imgcodecs/src/loadsave.cpp
@@ -651,8 +651,15 @@ imdecode_( const Mat& buf, int flags, int hdrtype, Mat* mat=0 )
         if( !f )
             return 0;
         size_t bufSize = buf.cols*buf.rows*buf.elemSize();
-        fwrite( buf.ptr(), 1, bufSize, f );
-        fclose(f);
+        if( fwrite( buf.ptr(), 1, bufSize, f ) != bufSize )
+        {
+            fclose( f );
+            CV_Error( CV_StsError, "failed to write image data to temporary file" );
+        }
+        if( fclose(f) != 0 )
+        {
+            CV_Error( CV_StsError, "failed to write image data to temporary file" );
+        }
         decoder->setSource(filename);
     }
 
