FIX: WRITE on file-port does not update file size (posix fix)

resolves: Oldes/Rebol-issues#552

Author: Oldes

src/os/posix/dev-file.c

@@ -486,6 +486,7 @@ static int Get_File_Info(REBREQ *file)
 ***********************************************************************/
 {
 	ssize_t num_bytes;
+	struct stat info;
 
 	if (!file->id) {
 		file->error = -RFE_NO_HANDLE;
@@ -512,8 +513,13 @@ static int Get_File_Info(REBREQ *file)
 		else file->error = -RFE_BAD_WRITE;
 		return DR_ERROR;
 	} else {
+		//SET_FLAG(file->modes, RFM_RESEEK);
 		file->actual = (u32)num_bytes;
 	}
+	if (fstat(file->id, &info) == 0) {
+		file->file.size = info.st_size;
+		file->file.time.l = (i32)(info.st_mtime);
+	}
 
 	return DR_DONE;
 }

src/tests/units/port-test.r3

@@ -337,6 +337,21 @@ if system/platform = 'Windows [
 		--assert "Hella World! Goodbye World!" = to-string read/seek f 0
 		--assert port? close f
 		try [delete %file-552]
+		--assert all [
+			port? p: open/new %file-552
+			file? write p "a"
+			tail? read p
+			file? write p "b"
+			tail? read p
+			#{6162} = read/seek p 0
+			tail? read p
+			file? write/seek p "c" 0
+			#{62} = read p
+			#{6362} = read/seek p 0
+			2 = length? p
+			port? close p
+		]
+		try [delete %file-552]
 
 	--test-- "clear file port"
 		;@@ https://github.com/Oldes/Rebol-issues/issues/812