Per the man page, setvbuf() must be called before any other operation on an open file.

We use setvbuf() to associate a buffer with a stream, but we have already written
to the open file.  This works (by chance) on Linux, but fails on other platforms,
such as OpenSolaris.

(closes issue #16610)
Reported by: bklang
Patches:
      setvbuf.patch uploaded by crjw (license 963)
Tested by: bklang, asgaroth, efutch


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.2@304096 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/file.c

@@ -1117,6 +1117,11 @@ struct ast_filestream *ast_writefile(const char *filename, const char *type, con
 		if (fd > -1) {
 			errno = 0;
 			fs = get_filestream(f, bfile);
+			if (fs) {
+				if ((fs->write_buffer = ast_malloc(32768))) {
+					setvbuf(fs->f, fs->write_buffer, _IOFBF, 32768);
+				}
+			}
 			if (!fs || rewrite_wrapper(fs, comment)) {
 				ast_log(LOG_WARNING, "Unable to rewrite %s\n", fn);
 				close(fd);
@@ -1143,11 +1148,6 @@ struct ast_filestream *ast_writefile(const char *filename, const char *type, con
 			}
 			fs->vfs = NULL;
 			/* If truncated, we'll be at the beginning; if not truncated, then append */
-
-			if ((fs->write_buffer = ast_malloc(32768))){
-				setvbuf(fs->f, fs->write_buffer, _IOFBF, 32768);
-			}
-
 			f->seek(fs, 0, SEEK_END);
 		} else if (errno != EEXIST) {
 			ast_log(LOG_WARNING, "Unable to open file %s: %s\n", fn, strerror(errno));