Bad remote file systems can change mtime unexpectedly, and then there is the problem that git rebase and similar operations like to change the files and then change them back, modifying the mtimes but not the content. Avoid spurious Put errors on both of those by checking file content. (False positive "modified since last read" make the real ones difficult to notice.)

Reading /mnt/acme/log reports a log of window create, put, and delete events, as they happen. It blocks until the next event is available. Example log output: 8 new /Users/rsc/foo.go 8 put /Users/rsc/foo.go 8 del /Users/rsc/foo.go This lets acme-aware programs react to file writes, for example compiling code, running a test, or updating an import block. TBR=r R=r https://codereview.appspot.com/89560044

R=rsc, r CC=plan9port.codebot http://codereview.appspot.com/6586067

Home and End previously navigated between two different window locations: the top and the bottom of the text. Now they include a third waypoint: the location where typing last happened. Thus, in a win window, typing ls -l <home> scrolls to the beginning of the ls -l output. A second <home> continues to the top of the file. Makes Send scroll always, along with writes by external programs to +Errors. R=r CC=mccoyst http://codereview.appspot.com/4830051

Ignore scroll/noscroll window setting. Instead, scroll when the write begins in or immediately after the displayed window content. In the new scrolling discipline, executing "Noscroll" is replaced by typing Page Up or using the mouse to scroll higher in the buffer, and executing "Scroll" is replaced by typing End or using the mouse to scroll to the bottom of the buffer. R=r, r2 http://codereview.appspot.com/4433060

to an actual flag. buffer underrun check in number add xdata file for exactly the addressed region save addr across opens

More changes.

Move libfmt, libutf into subdirectories of lib9. Add poll-based socket i/o to libthread, so that we can avoid using multiple procs when possible, thus removing dependence on crappy pthreads implementations. Convert samterm, acme to the single-proc libthread. Bring libcomplete, acme up-to-date w.r.t. Plan 9 distribution.