Always advance the record number on read record from FCB

dmsc · dmsc · commit c01cfa8d9698 · 2022-01-19T13:57:53.000-03:00
This fixes end-of-file detection when the file size is not a multiple of the record size. Fixes dmsc#33.
diff --git a/src/dos.c b/src/dos.c
@@ -382,7 +382,7 @@ static int dos_rw_record_fcb(int addr, int write, int update, int seq)
     // Update random and block positions
     if(update)
     {
-        unsigned rnum = (pos + n) / rsize;
+        unsigned rnum = (pos + ((n>0) ? rsize : 0)) / rsize;
         memory[0x20 + fcb] = rnum & 127;
         put16(0x0C + fcb, rnum / 128);
         if(!seq)

Original file line number	Diff line number	Diff line change
`@@ -382,7 +382,7 @@ static int dos_rw_record_fcb(int addr, int write, int update, int seq)`
`382`	`382`	`// Update random and block positions`
`383`	`383`	`if(update)`
`384`	`384`	`{`
`385`		`- unsigned rnum = (pos + n) / rsize;`
	`385`	`+ unsigned rnum = (pos + ((n>0) ? rsize : 0)) / rsize;`
`386`	`386`	`memory[0x20 + fcb] = rnum & 127;`
`387`	`387`	`put16(0x0C + fcb, rnum / 128);`
`388`	`388`	`if(!seq)`