On Fri, Mar 04, 2016 at 12:54:42PM +0100, Peter Klotz wrote: > Hello Subversion Developers > > We encountered a strange issue with Subversion 1.9.3 (running under RHEL 7). > The attached script demonstrates the behavior. > > When changing the timestamp of a file to an earlier point in time and leaving > the file size unchanged yet altering the content, Subversion is not always > able to detect this change. > The attached test case is the simplest we could come up with that reliably > reproduces the problem. > > Regards, Peter.
Subversion uses timestamp and size as a short-cut for detecting unmodified files. This saves Subversion from having to run a full content comparison for every file in the working copy when 'svn status' is run under what we'd consider "normal" conditions. You are artificially creating conditions which fool Subversion into believing the file was not modified. Because the timestamps and size checks which precede a full content comparison indicate the file was not modified, the full content comparison is skipped and the modification remains undetected. So, that's why you're seeing this behaviour. What's unclear is why you are investigating this behaviour in the first place. What is your use case for changing the file's content but leaving it's timestamp unchanged? Does the use-commit-times option help your use case, perhaps? See http://svnbook.red-bean.com/nightly/en/svn.advanced.confarea.html#svn.advanced.confarea.opts and search for 'use-commit-times' on this page.
