Re: opencvs - fix revision lookups for branches

[Joris Vink]

On Wed, Jun 22, 2016 at 09:07:03AM -0600, Todd C. Miller wrote:
> On Wed, 22 Jun 2016 12:21:56 +0200, Joris Vink wrote:
> > Index: rcs.c
> > ===================================================================
> > RCS file: /cvs/src/usr.bin/cvs/rcs.c,v
> > retrieving revision 1.313
> > diff -u -p -r1.313 rcs.c
> > --- rcs.c   5 Nov 2015 09:48:21 -0000       1.313
> > +++ rcs.c   22 Jun 2016 09:52:04 -0000
> > @@ -1796,17 +1796,13 @@ rcs_rev_getlines(RCSFILE *rfp, RCSNUM *f
> >  
> >  again:
> >     for (;;) {
> > +           if (rdp == NULL)
> > +                   break;
> 
> Wouldn't this be easier to read as:
> 
>       while (rdp != NULL) {

Yes, updated diff below.

.joris

Index: rcs.c
===================================================================
RCS file: /cvs/src/usr.bin/cvs/rcs.c,v
retrieving revision 1.313
diff -u -p -r1.313 rcs.c
--- rcs.c       5 Nov 2015 09:48:21 -0000       1.313
+++ rcs.c       22 Jun 2016 15:13:14 -0000
@@ -1795,18 +1795,11 @@ rcs_rev_getlines(RCSFILE *rfp, RCSNUM *f
                goto done;
 
 again:
-       for (;;) {
+       while (rdp != NULL) {
                if (rdp->rd_next->rn_len != 0) {
                        trdp = rcs_findrev(rfp, rdp->rd_next);
                        if (trdp == NULL)
                                fatal("failed to grab next revision");
-               } else {
-                       /*
-                        * XXX Fail, although the caller does not always do the
-                        * right thing (eg cvs diff when the tree is ahead of
-                        * the repository).
-                        */
-                       break;
                }
 
                if (rdp->rd_tlen == 0) {
@@ -1857,7 +1850,7 @@ again:
        }
 
 next:
-       if (!rcsnum_differ(rdp->rd_num, frev))
+       if (rdp == NULL || !rcsnum_differ(rdp->rd_num, frev))
                done = 1;
 
        if (RCSNUM_ISBRANCHREV(frev) && done != 1) {
@@ -2045,6 +2038,7 @@ rcs_rev_getbuf(RCSFILE *rfp, RCSNUM *rev
        struct rcs_delta *rdp;
        struct rcs_lines *lines;
        struct rcs_line *lp, *nlp;
+       char version[RCSNUM_MAXSTR];
        BUF *bp;
 
        rdp = NULL;
@@ -2057,8 +2051,12 @@ rcs_rev_getbuf(RCSFILE *rfp, RCSNUM *rev
                expmode = rcs_kwexp_get(rfp);
 
                if (!(expmode & RCS_KWEXP_NONE)) {
-                       if ((rdp = rcs_findrev(rfp, rev)) == NULL)
-                               fatal("could not fetch revision");
+                       if ((rdp = rcs_findrev(rfp, rev)) == NULL) {
+                               rcsnum_tostr(rev, version, sizeof(version));
+                               fatal("could not find desired version %s in %s",
+                                   version, rfp->rf_path);
+                       }
+
                        expand = 1;
                }
        }