FIX: update file info after clearing file-port (posix)

related to: Oldes/Rebol-issues#812 and Oldes/Rebol-issues#552

Author: Oldes

src/os/posix/dev-file.c

@@ -487,7 +487,8 @@ static int Get_File_Info(REBREQ *file)
 {
 	ssize_t num_bytes;
 	struct stat info;
-
+	file->actual = 0;
+	
 	if (!file->id) {
 		file->error = -RFE_NO_HANDLE;
 		return DR_ERROR;
@@ -505,17 +506,17 @@ static int Get_File_Info(REBREQ *file)
 			if (ftruncate(file->id, file->file.index)) return DR_ERROR;
 	}
 
-	if (file->length == 0) return DR_DONE;
-
-	num_bytes = write(file->id, file->data, file->length);
-	if (num_bytes < 0) {
-		if (errno == ENOSPC) file->error = -RFE_DISK_FULL;
-		else file->error = -RFE_BAD_WRITE;
-		return DR_ERROR;
-	} else {
-		//SET_FLAG(file->modes, RFM_RESEEK);
-		file->actual = (u32)num_bytes;
+	if (file->length > 0) {
+		num_bytes = write(file->id, file->data, file->length);
+		if (num_bytes < 0) {
+			if (errno == ENOSPC) file->error = -RFE_DISK_FULL;
+			else file->error = -RFE_BAD_WRITE;
+			return DR_ERROR;
+		} else {
+			file->actual = (u32)num_bytes;
+		}
 	}
+	// update new file info
 	if (fstat(file->id, &info) == 0) {
 		file->file.size = info.st_size;
 		file->file.time.l = (i32)(info.st_mtime);

src/tests/units/port-test.r3

@@ -365,10 +365,12 @@ if system/platform = 'Windows [
 			file? write %file-812 "Hello World!"
 			port? f: open %file-812
 			"Hello World!" = read/string f
+			13 = index? f
 			port? clear f ; this actually does not clear the file as we are at the end of the stream
 			0  = length? f
 			12 =   size? f
 			"Hello" = read/seek/string/part f 0 5
+			6  =  index? f
 			7  = length? f
 			12 =   size? f
 			port? clear f ; this should truncate the file