Merge from vendor branch GCC:
[dragonfly.git] / contrib / cvs-1.12 / TODO
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1The "TODO" file! -*-Indented-Text-*-
2
338. Think hard about using RCS state information to allow one to checkin
4 a new vendor release without having it be accessed until it has been
5 integrated into the local changes.
6
739. Think about a version of "cvs update -j" which remembers what from
8 that other branch is already merged. This has pitfalls--it could
9 easily lead to invisible state which could confuse users very
10 rapidly--but having to create a tag or some such mechanism to keep
11 track of what has been merged is a pain. Take a look at PRCS 1.2.
12 PRCS 1.0 was particularly bad the way it handled the "invisible
13 state", but 1.2 is significantly better.
14
1552. SCCS has a feature that I would *love* to see in CVS, as it is very
16 useful. One may make a private copy of SCCS suid to a particular user,
17 so other users in the authentication list may check files in and out of
18 a project directory without mucking about with groups. Is there any
19 plan to provide a similar functionality to CVS? Our site (and, I'd
20 imagine, many other sites with large user bases) has decided against
21 having the user-groups feature of unix available to the users, due to
22 perceived administrative, technical and performance headaches. A tool
23 such as CVS with features that provide group-like functionality would
24 be a huge help.
25
2662. Consider using revision controlled files and directories to handle the
27 new module format -- consider a cvs command front-end to
28 add/delete/modify module contents, maybe.
29
3063. The "import" and vendor support commands (co -j) need to be documented
31 better.
32
3366. Length of the CVS temporary files must be limited to 14 characters for
34 System-V stupid support. As well as the length on the CVS.adm files.
35
3672. Consider re-design of the module -t options to use the file system more
37 intuitively.
38
3973. Consider an option (in .cvsrc?) to automatically add files that are new
40 and specified to commit.
41
4279. Might be nice to have some sort of interface to Sun's Translucent
43 (?) File System and tagged revisions.
44
4582. Maybe the import stuff should allow an arbitrary revision to be
46 specified.
47
4884. Improve the documentation about administration of the repository and
49 how to add/remove files and the use of symbolic links.
50
5185. Make symbolic links a valid thing to put under version control.
52 Perhaps use one of the tag fields in the RCS file? Note that we
53 can only support symlinks that are relative and within the scope of
54 the sources being controlled.
55
5693. Need to think hard about release and development environments. Think
57 about execsets as well.
58
5998. If diff3 bombs out (too many differences) cvs then thinks that the file
60 has been updated and is OK to be commited even though the file
61 has not yet been merged.
62
63100. Checked out files should have revision control support. Maybe.
64
65102. Perhaps directory modes should be propagated on all import check-ins.
66 Not necessarily uid/gid changes.
67
68103. setuid/setgid on files is suspect.
69
70104. cvs should recover nicely on unreadable files/directories.
71
72105. cvs should have administrative tools to allow for changing permissions
73 and modes and what not. In particular, this would make cvs a
74 more attractive alternative to rdist.
75
76107. It should be possible to specify a list of symbolic revisions to
77 checkout such that the list is processed in reverse order looking for
78 matches within the RCS file for the symbolic revision. If there is
79 not a match, the next symbolic rev on the list is checked, and so on,
80 until all symbolic revs are exhausted. This would allow one to, say,
81 checkout "4.0" + "4.0.3" + "4.0.3Patch1" + "4.0.3Patch2" to get the
82 most recent 4.x stuff. This is usually handled by just specifying the
83 right release_tag, but most people forget to do this.
84
85108. If someone creates a whole new directory (i.e. adds it to the cvs
86 repository) and you happen to have a directory in your source farm by
87 the same name, when you do your cvs update -d it SILENTLY does
88 *nothing* to that directory. At least, I think it was silent;
89 certainly, it did *not* abort my cvs update, as it would have if the
90 same thing had happened with a file instead of a directory.
91
92109. I had gotten pieces of the sys directory in the past but not a
93 complete tree. I just did something like:
94
95 cvs get *
96
97 Where sys was in * and got the message
98
99 cvs get: Executing 'sys/tools/make_links sys'
100 sh: sys/tools/make_links: not found
101
102 I suspect this is because I didn't have the file in question,
103 but I do not understand how I could fool it into getting an
104 error. I think a later cvs get sys seemed to work so perhaps
105 something is amiss in handling multiple arguments to cvs get?
106
107119. When importing a directory tree that is under SCCS/RCS control,
108 consider an option to have import checkout the SCCS/RCS files if
109 necessary. (This is if someone wants to import something which
110 is in RCS or SCCS without preserving the history, but makes sure
111 they do get the latest versions. It isn't clear to me how useful
112 that is -kingdon, June 1996).
113
114122. If Name_Repository fails, it currently causes CVS to die completely. It
115 should instead return NULL and have the caller do something reasonable
116 (??? -what is reasonable? I'm not sure there is a real problem here.
117 -kingdon, June 1996).
118
119123. Add a flag to import to not build vendor branches for local code.
120 (See `importb' tests in src/sanity.sh for more details).
121
122124. Anyway, I thought you might want to add something like the following
123 to the cvs man pages:
124
125 BUGS
126 The sum of the sizes of a module key and its contents are
127 limited. See ndbm(3).
128
129126. Do an analysis to see if CVS is forgetting to close file descriptors.
130 Especially when committing many files (more than the open file limit
131 for the particular UNIX).
132
133127. Look at *info files; they should all be quiet if the files are not
134 there. Should be able to point at a RCS directory and go.
135
136130. cvs diff with no -r arguments does not need to look up the current RCS
137 version number since it only cares about what's in the Entries file.
138 This should make it much faster.
139
140 It should ParseEntries itself and access the entries list much like
141 Version_TS does (sticky tags and sticky options may need to be
142 supported here as well). Then it should only diff the things that
143 have the wrong time stamp (the ones that look modified).
144
145134. Make a statement about using hard NFS mounts to your source
146 repository. Look into checking NULL fgets() returns with ferror() to
147 see if an error had occurred. (we should be checking for errors, quite
148 aside from NFS issues -kingdon, June 1996).
149
150137. Some sites might want CVS to fsync() the RCS ,v file to protect
151 against nasty hardware errors. There is a slight performance hit with
152 doing so, though, so it should be configurable in the .cvsrc file.
153 Also, along with this, we should look at the places where CVS itself
154 could be a little more synchronous so as not to lose data.
155 [[ I've done some of this, but it could use much more ]]
156
157138. Some people have suggested that CVS use a VPATH-like environment
158 variable to limit the amount of sources that need to be duplicated for
159 sites with giant source trees and no disk space.
160
161141. Import should accept modules as its directory argument. If we're
162 going to implement this, we should think hard about how modules
163 might be expanded and how to handle those cases.
164
165143. Update the documentation to show that the source repository is
166 something far away from the files that you work on. (People who
167 come from an RCS background are used to their `repository' being
168 _very_ close to their working directory.)
169
170144. Have cvs checkout look for the environment variable CVSPREFIX
171 (or CVSMODPREFIX or some such). If it's set, then when looking
172 up an alias in the modules database, first look it up with the
173 value of CVSPREFIX attached, and then look for the alias itself.
174 This would be useful when you have several projects in a single
175 repository. You could have aliases abc_src and xyz_src and
176 tell people working on project abc to put "setenv CVSPREFIX abc_"
177 in their .cshrc file (or equivalent for other shells).
178 Then they could do "cvs co src" to get a copy of their src
179 directory, not xyz's. (This should create a directory called
180 src, not abc_src.)
181
182145. After you create revision 1.1.1.1 in the previous scenario, if
183 you do "cvs update -r1 filename" you get revision 1.1, not
184 1.1.1.1. It would be nice to get the later revision. Again,
185 this restriction comes from RCS and is probably hard to
186 change in CVS. Sigh.
187
188 |"cvs update -r1 filename" does not tell RCS to follow any branches. CVS
189 |tries to be consistent with RCS in this fashion, so I would not change
190 |this. Within CVS we do have the flexibility of extending things, like
191 |making a revision of the form "-r1HEAD" find the most recent revision
192 |(branch or not) with a "1." prefix in the RCS file. This would get what
193 |you want maybe.
194
195 This would be very useful. Though I would prefer an option
196 such as "-v1" rather than "-r1HEAD". This option might be
197 used quite often.
198
199146. The merging of files should be controlled via a hook so that programs
200 other than "rcsmerge" can be used, like Sun's filemerge or emacs's
201 emerge.el. (but be careful in making this work client/server--it means
202 doing the interactive merging at the end after the server is done).
203 (probably best is to have CVS do the non-interactive part and
204 tell the user about where the files are (.#foo.c.working and
205 .#foo.c.1.5 or whatever), so they can do the interactive part at
206 that point -kingdon, June 1996).
207
208149. Maybe there should be an option to cvs admin that allows a user to
209 change the Repository/Root file with some degree of error checking?
210 Something like "cvs admin reposmv /old/path /new/pretty/path". Before
211 it does the replace it check to see that the files
212 /new/pretty/path/<dir>/<files> exist.
213
214 The obvious cases are where one moves the repository to another
215 machine or directory. But there are other cases, like where the
216 user might want to change from :pserver: to :ext:, use a different
217 server (if there are two server machines which share the
218 repository using a networked file system), etc.
219
220 The status quo is a bit of a mess (as of, say, CVS 1.9). It is
221 that the -d global option has two moderately different uses. One
222 is to use a totally different repository (in which case we'd
223 probably want to give an error if it disagreed with CVS/Root, as
224 CVS 1.8 and earlier did). The other is the "reposmv"
225 functionality above (in which the two repositories really are the
226 same, and we want to update the CVS/Root files). In CVS 1.9 and
227 1.10, -d rewrites the CVS/Root file (but not in subdirectories).
228 This behavior was not particularly popular and has been since
229 reverted.
230
231 This whole area is a rather bad pile of individual decisions which
232 accumulated over time, some of them probably bad decisions with
233 hindsight. But we didn't get into this mess overnight, and we're
234 not going to get out of it overnight (that is, we need to come up
235 with a replacement behavior, document what parts of the status
236 quo are deprecated, probably circulate some unofficial patches, &c).
237
238 (this item originally added 2 Feb 1992 but revised since).
239
240150. I have a customer request for a way to specify log message per
241 file, non-interactively before the commit, such that a single, fully
242 recursive commit prompts for one commit message, and concatenates the
243 per file messages for each file. In short, one commit, one editor
244 session, log messages allowed to vary across files within the commit.
245 Also, the per file messages should be allowed to be written when the
246 files are changed, which may predate the commit considerably.
247
248 A new command seems appropriate for this. The state can be saved in the
249 CVS directory. I.e.,
250
251 % cvs message foo.c
252 Enter log message for foo.c
253 >> fixed an uninitialized variable
254 >> ^D
255
256 The text is saved as CVS/foo.c,m (or some such name) and commit
257 is modified to append (prepend?) the text (if found) to the log
258 message specified at commit time. Easy enough. (having cvs
259 commit be non-interactive takes care of various issues like
260 whether to connect to the server before or after prompting for a
261 message (see comment in commit.c at call to start_server). Also
262 would clean up the kludge for what to do with the message from
263 do_editor if the up-to-date check fails (see commit.c client code).
264
265 I'm not sure about the part above about having commit prompt
266 for an overall message--part of the point is having commit
267 non-interactive and somehow combining messages seems like (excess?)
268 hair.
269
270 Would be nice to do this so it allows users more flexibility in
271 specifying messages per-directory ("cvs message -l") or per-tree
272 ("cvs message") or per-file ("cvs message foo.c"), and fixes the
273 incompatibility between client/server (per-tree) and
274 non-client/server (per-directory).
275
276 A few interesting issues with this: (1) if you do a cvs update or
277 some other operation which changes the working directory, do you
278 need to run "cvs message" again (it would, of course, bring up
279 the old message which you could accept)? Probably yes, after all
280 merging in some conflicts might change the situation. (2) How do
281 you change the stored messages if you change your mind before the
282 commit (probably run "cvs message" again, as hinted in (1))?
283
284151. Also, is there a flag I am missing that allows replacing Ulrtx_Build
285 by Ultrix_build? I.E. I would like a tag replacement to be a one step
286 operation rather than a two step "cvs rtag -r Ulrtx_Build Ultrix_Build"
287 followed by "cvs rtag -d Ulrtx_Build"
288
289152. The "cvs -n" option does not work as one would expect for all the
290 commands. In particular, for "commit" and "import", where one would
291 also like to see what it would do, without actually doing anything.
292
293153. There should be some command (maybe I just haven't figured out
294 which one...) to import a source directory which is already
295 RCS-administered without losing all prior RCS gathered data.
296 Thus, it would have to examine the RCS files and choose a
297 starting version and branch higher than previous ones used.
298 (Check out rcs-to-cvs and see if it addresses this issue.)
299
300154. When committing the modules file, a pre-commit check should be done to
301 verify the validity of the new modules file before allowing it to be
302 committed.
303
304155. The options for "cvs history" are mutually exclusive, even though
305 useful queries can be done if they are not, as in specifying both
306 a module and a tag. A workaround is to specify the module, then
307 run the output through grep to only display lines that begin with
308 T, which are tag lines. (Better perhaps if we redesign the whole
309 "history" business -- check out doc/cvs.texinfo for the entire
310 rant.)
311
312156. Also, how hard would it be to allow continuation lines in the
313 {commit,rcs,log}info files? It would probably be useful with all of
314 the various flags that are now available, or if somebody has a lot of
315 files to put into a module.
316
317158. If I do a recursive commit and find that the same RCS file is checked
318 out (and modified!) in two different places within my checked-out
319 files (but within the realm of a single "commit"), CVS will commit the
320 first change, then overwrite that change with the second change. We
321 should catch this (typically unusual) case and issue an appropriate
322 diagnostic and die.
323
324160. The checks that the commit command does should be extended to make
325 sure that the revision that we will lock is not already locked by
326 someone else. Maybe it should also lock the new revision if the old
327 revision was already locked by the user as well, thus moving the lock
328 forward after the commit.
329
330163. The rtag/tag commands should have an option that removes the specified
331 tag from any file that is in the attic. This allows one to re-use a
332 tag (like "Mon", "Tue", ...) all the time and still have it tag the
333 real main-line code.
334
335165. The "import" command will create RCS files automatically, but will
336 screw-up when trying to create long file names on short file name
337 file systems. Perhaps import should be a bit more cautious.
338
339166. There really needs to be a "Getting Started" document which describes
340 some of the new CVS philosophies. Folks coming straight from SCCS or
341 RCS might be confused by "cvs import". Also need to explain:
342 - How one might setup their $CVSROOT
343 - What all the tags mean in an "import" command
344 - Tags are important; revision numbers are not
345
346170. Is there an "info" file that can be invoked when a file is checked out, or
347 updated ? What I want to do is to advise users, particularly novices, of
348 the state of their working source whenever they check something out, as
349 a sanity check.
350
351 For example, I've written a perl script which tells you what branch you're
352 on, if any. Hopefully this will help guard against mistaken checkins to
353 the trunk, or to the wrong branch. I suppose I can do this in
354 "commitinfo", but it'd be nice to advise people before they edit their
355 files.
356
357 It would also be nice if there was some sort of "verboseness" switch to
358 the checkout and update commands that could turn this invocation of the
359 script off, for mature users.
360
361173. Need generic date-on-branch handling. Currently, many commands
362 allow both -r and -D, but that's problematic for commands like diff
363 that interpret that as two revisions rather than a single revision.
364 Checkout and update -j takes tag:date which is probably a better
365 solution overall.
366
367174. I would like to see "cvs release" modified so that it only removes files
368 which are known to CVS - all the files in the repository, plus those which
369 are listed in .cvsignore. This way, if you do leave something valuable in
370 a source tree you can "cvs release -d" the tree and your non-CVS goodies
371 are still there. If a user is going to leave non-CVS files in their source
372 trees, they really should have to clean them up by hand.
373
374175. And, in the feature request department, I'd dearly love a command-line
375 interface to adding a new module to the CVSROOT/modules file.
376
377176. If you use the -i flag in the modules file, you can control access
378 to source code; this is a Good Thing under certain circumstances. I
379 just had a nasty thought, and on experiment discovered that the
380 filter specified by -i is _not_ run before a cvs admin command; as
381 this allows a user to go behind cvs's back and delete information
382 (cvs admin -o1.4 file) this seems like a serious problem.
383
384177. We've got some external vendor source that sits under a source code
385 hierarchy, and when we do a cvs update, it gets wiped out because
386 its tag is different from the "main" distribution. I've tried to
387 use "-I" to ignore the directory, as well as .cvsignore, but this
388 doesn't work.
389
390179. "cvs admin" does not log its actions with loginfo, nor does it check
391 whether the action is allowed with commitinfo. It should.
392
393182. There should be a way to show log entries corresponding to
394changes from tag "foo" to tag "bar". "cvs log -rfoo:bar" doesn't cut
395it, because it erroneously shows the changes associated with the
396change from the revision before foo to foo. I'm not sure that is ever
397a useful or logical behavior ("cvs diff -r foo -r bar" gets this
398right), but is compatibility an issue? See
399http://www.cyclic.com/cvs/unoff-log.txt for an unofficial patch.
400
401183. "cvs status" should report on Entries.Static flag and CVS/Tag (how?
402maybe a "cvs status -d" to give directory status?). There should also
403be more documentation of how these get set and how/when to re-set them.
404
405184. Would be nice to implement the FreeBSD MD5-based password hash
406algorithm in pserver. For more info see "6.1. DES, MD5, and Crypt" in
407the FreeBSD Handbook, and src/lib/libcrypt/crypt.c in the FreeBSD
408sources. Certainly in the context of non-unix servers this algorithm
409makes more sense than the traditional unix crypt() algorithm, which
410suffers from export control problems.
411
412185. A frequent complaint is that keyword expansion causes conflicts
413when merging from one branch to another. The first step is
414documenting CVS's existing features in this area--what happens with
415various -k options in various places? The second step is thinking
416about whether there should be some new feature and if so how it should
417be designed. For example, here is one thought:
418
419 rcs' co command needs a new -k option. The new option should expand
420 $Log entries without expanding $Revision entries. This would
421 allow cvs to use rcsmerge in such a way that joining branches into
422 main lines would neither generate extra collisions on revisions nor
423 drop log lines.
424
425The details of this are out of date (CVS no longer invokes "co", and
426any changes in this area would be done by bypassing RCS rather than
427modifying it), but even as to the general idea, I don't have a clear
428idea about whether it would be good (see what I mean about the need
429for better documentation? I work on CVS full-time, and even I don't
430understand the state of the art on this subject).
431
432186. There is a frequent discussion of multisite features.
433
434* There may be some overlap with the client/server CVS, which is good
435especially when there is a single developer at each location. But by
436"multisite" I mean something in which each site is more autonomous, to
437one extent or another.
438
439* Vendor branches are the closest thing that CVS currently has for
440multisite features. They have fixable drawbacks (such as poor
441handling of added and removed files), and more fundamental drawbacks
442(when you import a vendor branch, you are importing a set of files,
443not importing any knowledge of their version history outside the
444current repository).
445
446* One approach would be to require checkins (or other modifications to
447the repository) to succeed at a write quorum of sites (51%) before
448they are allowed to complete. To work well, the network should be
449reliable enough that one can typically get to that many sites. When a
450server which has been out of touch reconnects, it would want to update
451its data before doing anything else. Any of the servers can service
452all requests locally, except perhaps for a check that they are
453up-to-date. The way this differs from a run-of-the-mill distributed
454database is that if one only allows reversible operations via this
455mechanism (exclude "cvs admin -o", "cvs tag -d", &c), then each site
456can back up the others, such that failures at one site, including
457something like deleting all the sources, can be recovered from. Thus
458the sites need not trust each other as much as for many shared
459databases, and the system may be resilient to many types of
460organizational failures. Sometimes I call this design the
461"CVScluster" design.
462
463* Another approach is a master/slave one. Checkins happen at the
464master site, and slave sites need to check whether their local
465repository is up to date before relying on its information.
466
467* Another approach is to have each site own a particular branch. This
468one is the most tolerant of flaky networks; if checkins happen at each
469site independently there is no particular problem. The big question
470is whether merges happen only manually, as with existing CVS branches,
471or whether there is a feature whereby there are circumstances in which
472merges from one branch to the other happen automatically (for example,
473the case in which the branches have not diverged). This might be a
474legitimate question to ask even quite aside from multisite features.
475
476187. Might want to separate out usage error messages and help
477messages. The problem now is that if you specify an invalid option,
478for example, the error message is lost among all the help text. In
479the new regime, the error message would be followed by a one-line
480message directing people to the appropriate help option ("cvs -H
481<command>" or "cvs --help-commands" or whatever, according to the
482situation). I'm not sure whether this change would be controversial
483(as defined in HACKING), so there might be a need for further
484discussion or other actions other than just coding.
485
486188. Option parsing and .cvsrc has at least one notable limitation.
487If you want to set a global option only for some CVS commands, there
488is no way to do it (for example, if one wants to set -q only for
489"rdiff"). I am told that the "popt" package from RPM
490(http://www.rpm.org) could solve this and other problems (for example,
491if the syntax of option stuff in .cvsrc is similar to RPM, that would
492be great from a user point of view). It would at least be worth a
493look (it also provides a cleaner API than getopt_long).
494
495Another issue which may or may not be related is the issue of
496overriding .cvsrc from the command line. The cleanest solution might
497be to have options in mutually exclusive sets (-l/-R being a current
498example, but --foo/--no-foo is a better way to name such options). Or
499perhaps there is some better solution.
500
501189. Renaming files and directories is a frequently discussed topic.
502
503Some of the problems with the status quo:
504
505a. "cvs annotate" cannot operate on both the old and new files in a
506single run. You need to run it twice, once for the new name and once
507for the old name.
508
509b. "cvs diff" (or "cvs diff -N") shows a rename as a removal of the
510old file and an addition of the new one. Some people would like to
511see the differences between the file contents (but then how would we
512indicate the fact that the file has been renamed? Certainly the
513notion that "patch(1)" has of renames is as a removal and addition).
514
515c. "cvs log" should be able to show the changes between two
516tags/dates, even in the presence of adds/removes/renames (I'm not sure
517what the status quo is on this; see also item #182).
518
519d. Renaming directories is way too hard.
520
521Implementations:
522
523It is perhaps premature to try to design implementation details
524without answering some of the above questions about desired behaviors
525but several general implementations get mentioned.
526
527i. No fundamental changes (for example, a "cvs rename" command which
528operated on directories could still implement the current recommended
529practice for renaming directories, which is to rename each of the
530files contained therein via an add and a remove). One thing to note
531that the status quo gets right is proper merges, even with adds and
532removals (Well, mostly right at least. There are a *LOT* of different
533cases; see the testsuite for some of them).
534
535ii. Rename database. In this scheme the files in the repository
536would have some arbitrary name, and then a separate rename database
537would indicate the current correspondence between the filename in the
538working directory and the actual storage. As far as I know this has
539never been designed in detail for CVS.
540
541iii. A modest change in which the RCS files would contain some
542information such as "renamed from X" or "renamed to Y". That is, this
543would be generally similar to the log messages which are suggested
544when one renames via an add and a removal, but would be
545computer-parseable. I don't think anyone has tried to flesh out any
546details here either.
547
548It is interesting to note that in solution ii. version numbers in the
549"new file" start where the "old file" left off, while in solutions
550i. and iii., version numbers restart from 1.1 each time a file is
551renamed. Except perhaps in the case where we rename a file from foo
552to bar and then back to foo. I'll shut up now.
553
554Regardless of the method we choose, we need to address how renames
555affect existing CVS behaviors. For example, what happens when you
556rename a file on a branch but not the trunk and then try to merge the
557two? What happens when you rename a file on one branch and delete it
558on another and try to merge the two?
559
560Ideally, we'd come up with a way to parameterize the problem and
561simply write up a lookup table to determine the correct behavior.
562
563190. The meaning of the -q and -Q global options is very ad hoc;
564there is no clear definition of which messages are suppressed by them
565and which are not. Here is a classification of the current meanings
566of -q; I don't know whether anyone has done a similar investigation of
567-Q:
568
569 a. The "warm fuzzies" printed upon entering each directory (for
570 example, "cvs update: Updating sdir"). The need for these messages
571 may be decreased now that most of CVS uses ->fullname instead of
572 ->file in messages (a project which is *still* not 100% complete,
573 alas). However, the issue of whether CVS can offer status as it
574 runs is an important one. Of course from the command line it is
575 hard to do this well and one ends up with options like -q. But
576 think about emacs, jCVS, or other environments which could flash you
577 the latest status line so you can see whether the system is working
578 or stuck.
579
580 b. Other cases where the message just offers information (rather
581 than an error) and might be considered unnecessarily verbose. These
582 have a certain point to them, although it isn't really clear whether
583 it should be the same option as the warm fuzzies or whether it is
584 worth the conceptual hair:
585
586 add.c: scheduling %s `%s' for addition (may be an issue)
587 modules.c: %s %s: Executing '%s' (I can see how that might be noise,
588 but...)
589 remove.c: scheduling `%s' for removal (analogous to the add.c one)
590 update.c: Checking out %s (hmm, that message is a bit on the noisy side...)
591 (but the similar message in annotate is not affected by -q).
592
593 c. Suppressing various error messages. This is almost surely
594 bogus.
595
596 commit.c: failed to remove tag `%s' from `%s' (Questionable.
597 Rationale might be that we already printed another message
598 elsewhere but why would it be necessary to avoid
599 the extra message in such an uncommon case?)
600 commit.c: failed to commit dead revision for `%s' (likewise)
601 remove.c: file `%s' still in working directory (see below about rm
602 -f analogy)
603 remove.c: nothing known about `%s' (looks dubious to me, especially in
604 the case where the user specified it explicitly).
605 remove.c: removed `%s' (seems like an obscure enough case that I fail
606 to see the appeal of being cryptically concise here).
607 remove.c: file `%s' already scheduled for removal (now it is starting
608 to look analogous to the infamous rm -f option).
609 rtag.c: cannot find tag `%s' in `%s' (more rm -f like behavior)
610 rtag.c: failed to remove tag `%s' from `%s' (ditto)
611 tag.c: failed to remove tag %s from %s (see above about whether RCS_*
612 has already printed an error message).
613 tag.c: couldn't tag added but un-commited file `%s' (more rm -f
614 like behavior)
615 tag.c: skipping removed but un-commited file `%s' (ditto)
616 tag.c: cannot find revision control file for `%s' (ditto, but at first
617 glance seems even worse, as this would seem to be a "can't happen"
618 condition)
619
620191. Storing RCS files, especially binary files, takes rather more
621space than it could, typically.
622 - The virtue of the status quo is that it is simple to implement.
623 Of course it is also simplest in terms of dealing with compatibility.
624 - Just storing the revisions as separate gzipped files is a common
625 technique. It also is pretty simple (no new algorithms, CVS
626 already has zlib around). Of course for some files (such as files
627 which are already compressed) the gzip step won't help, but
628 something which can at least sometimes avoid rewriting the entire
629 RCS file for each new revision would, I would think, be a big
630 speedup for large files.
631 - Josh MacDonald has written a tool called xdelta which produces
632 differences (that is, sufficient information to transform the old
633 to the new) which looks for common sequences of bytes, like RCS
634 currently does, but which is not based on lines. This seems to do
635 quite well for some kinds of files (e.g. FrameMaker documents,
636 text files), and not as well for others (anything which is already
637 compressed, executables). xdelta 1.10 also is faster than GNU diff.
638 - Karl Fogel has thought some about using a difference technique
639 analogous to fractal compression (see the comp.compression FAQ for
640 more on fractal compression, including at least one patent to
641 watch for; I don't know how analogous Karl's ideas are to the
642 techniques described there).
643 - Quite possibly want some documented interface by which a site can
644 plug in their choice of external difference programs (with the
645 ability to choose the program based on filename, magic numbers,
646 or some such).
647
648192. "cvs update" using an absolute pathname does not work if the
649working directory is not a CVS-controlled directory with the correct
650CVSROOT. For example, the following will fail:
651
652 cd /tmp
653 cvs -d /repos co foo
654 cd /
655 cvs update /tmp/foo
656
657It is possible to read the CVSROOT from the administrative files in
658the directory specified by the absolute pathname argument to update.
659In that case, the last command above would be equivalent to:
660
661 cd /tmp/foo
662 cvs update .
663
664This can be problematic, however, if we ask CVS to update two
665directories with different CVSROOTs. Currently, CVS has no way of
666changing CVSROOT mid-stream. Consider the following:
667
668 cd /tmp
669 cvs -d /repos1 co foo
670 cvs -d /repos2 co bar
671 cd /
672 cvs update /tmp/foo /tmp/bar
673
674To make that example work, we need to think hard about:
675
676 - where and when CVSROOT-related variables get set
677 - who caches said variables for later use
678 - how the remote protocol should be extended to handle sending a new
679 repository mid-stream
680 - how the client should maintain connections to a variety of servers
681 in a single invocation.
682
683Because those issues are hairy, I suspect that having a change in
684CVSROOT be an error would be a better move.
685
686193. The client relies on timestamps to figure out whether a file is
687(maybe) modified. If something goes awry, then it ends up sending
688entire files to the server to be checked, and this can be quite slow
689especially over a slow network. A couple of things that can happen:
690(a) other programs, like make, use timestamps, so one ends up needing
691to do "touch foo" and otherwise messing with timestamps, (b) changing
692the timezone offset (e.g. summer vs. winter or moving a machine)
693should work on unix, but there may be problems with non-unix.
694
695Possible solutions:
696
697 a. Store a checksum for each file in CVS/Entries or some such
698 place. What to do about hash collisions is interesting: using a
699 checksum, like MD5, large enough to "never" have collisions
700 probably works in practice (of course, if there is a collision then
701 all hell breaks loose because that code path was not tested, but
702 given the tiny, tiny probability of that I suppose this is only an
703 aesthetic issue).
704
705 b. I'm not thinking of others, except storing the whole file in
706 CVS/Base, and I'm sure using twice the disk space would be
707 unpopular.
708
709194. CVS does not separate the "metadata" from the actual revision
710history; it stores them both in the RCS files. Metadata means tags
711and header information such as the number of the head revision.
712Storing the metadata separately could speed up "cvs tag" enormously,
713which is a big problem for large repositories. It could also probably
714make CVS's locking much less in the way (see comment in do_recursion
715about "two-pass design").
716
717195. Many people using CVS over a slow link are interested in whether
718the remote protocol could be any more efficient with network
719bandwidth. This item is about one aspect of that--how the server
720sends a new version of a file the client has a different version of,
721or vice versa.
722
723a. Cases in which the status quo already sends a diff. For most text
724files, this is probably already close to optimal. For binary files,
725and anomalous (?) text files (e.g. those in which it would help to do
726moves, as well as adds and deletes), it might be worth looking into other
727difference algorithms (see item #191).
728
729b. Cases in which the status quo does not send a diff (e.g. "cvs
730commit").
731
732b1. With some frequency, people suggest rsync or a similar algorithm
733(see ftp://samba.anu.edu.au/pub/rsync/). This could speed things up,
734and in some ways involves the most minimal changes to the default CVS
735paradigm. There are some downsides though: (1) there is an extra
736network turnaround, (2) the algorithm needs to transmit some data to
737discover what difference type programs can discover locally (although
738this is only about 1% of the size of the files).
739
740b2. If one is willing to require that users use "cvs edit" before
741editing a file on the client side (in some cases, a development
742environment like emacs can make this fairly easy), then the Modified
743request in the protocol could be extended to allow the client to just
744send differences instead of entire files. In the degenerate case
745(e.g. "cvs diff" without arguments) the required network traffic is
746reduced to zero, and the client need not even contact the server.
747
748197. Analyze the difference between CVS_UNLINK & unlink_file. As far as I
749can tell, unlink_file aborts in noexec mode and CVS_UNLINK does not. I'm not
750sure it would be possible to remove even the use of temp files in noexec mode,
751but most unlinks should probably be using unlink_file and not CVS_UNLINK.
752
753198. Remove references to deprecated cvs_temp_name function.
754
755199. Add test for login & logout functionality, including support for
756backwards compatibility with old CVSROOTs.
757
758200. Make a 'cvs add' without write access a non-fatal error so that
759the user's Entries file is updated and future 'cvs diffs' will work
760properly. This should ease patch submission.
761
762201. cvs_temp_file should be creating temporary files in a privately owned
763subdirectory of of temp due to security issues on some systems.
764
765202. Enable rdiff to accept most diff options. Make rdiff output look
766like diff's. Make CVS diff garbage go to stderr and only standard diff
767output go to stdout.
768
769203. Add val-tags additions to the tagging code. Don't remove the
770update additions since val-tags could still be used as a cache when the
771repository was imported from elsewhere (the tags weren't applied with a
772version which wrote val-tags).
773
774204. Add test case for compression. A buf_shutdown error using compression
775wasn't caught by the test suite.
776
777205. There are lots of cases where trailing slashes on directory names
778and other non-canonical paths confuse CVS. Most of the cases that do
779work are handled on an ad-hoc basis. We need to come up with a coherent
780strategy to address path canonicalization and apply it consistently.
781
782208. Merge enhancements to the diff package back into the original GNU source.
783
784209. Go through this file and try to:
785
786 a. Verify that items are still valid.
787
788 b. Create test cases for valid items when they don't exist.
789
790 c. Remove fixed and no longer applicable items.
791
792210. Explain to sanity.sh how to deal with paths with spaces and other odd
793characters in them.
794
795211. Make sanity.sh run under the Win32 bash (cygwin) and maybe other Windex
796environments (e.g. DGSS or whatever the MSVC portability environemnt is called).
797
798212. Autotestify (see autoconf source) sanity.sh.
799
800213. Examine desirability of updating the regex library (regex.{c,h}) to the
801more recent versions that come with glibc and emacs. It might be worth waiting
802for the emacs folks to get their act together and merge their changes into the
803glibc version.
804
805215. Add reditors and rwatchers commands.
806
807 - Is an r* command abstraction layer possible here for the commands
808 where this makes sense? Would it be simpler? It seems to me the
809 major operational differences lie in the file list construction.
810
811218. Fix "checkout -d ." in client/server mode.
812
813221. Handle spaces in file/directory names. (Most, if not all, of the
814internal infrastructure already handles them correctly, but most of the
815administrative file interfaces do not.)
816
817223. Internationalization support. This probably means using some kind
818of universal character set (ISO 10646?) internally and converting on
819input and output, which opens the locale can of worms.
820
821225. Add support for --allow-root to server command.
822
823227. 'cvs release' should use the CVS/Root in the directory being released
824when such is specified rather than $CVSROOT. In my work directory with no CVS
825dir, a release of subdirectories causes the released projects to be tested
826against my $CVSROOT environment variable, which often isn't correct but which
827can complete without generating error messages if the project also exists in
828the other CVSROOT. This happens a lot with my copies of the ccvs project.
829
830228. Consider adding -d to commit ala ci.
831
832229. Improve the locking code to use a random delay with exponential
833backoff ala Ethernet and separate the notification interval from the
834wait interval.
835
836230. Support for options like compression as part of the CVSROOT might be
837nice. This should be fairly easy to implement now using the method options.
838
839231. The `cvs watch off' command needs an extension which enables users in the
840cvsadmin group to turn watch off for users whose logins and email address may
841not exist anymore.
842
843232. Use file descriptor operations exclusively for I/O (not STDIO).
844
845233. The ls-D-2 test fails when run in the hour transition between daylight
846savings time and standard time. This probably has something to do with the
847two 1AM to 2AM time slots that occur over that two hour period (one such
848failure was on the morning of October 31st, 2004).
849
850234. Noop commands should be logged in the history file. Information can
851still be obtained with noop commands, for instance via `cvs -n up -p', and
852paranoid admins might appreciate this. Similarly, perhaps diff operations
853should be logged.