Apache Subversion - Limitations and Problems

Limitations and Problems

A known problem in Subversion affects the implementation of the file and directory rename operation. As of 2010, Subversion implements the renaming of files and directories as a "copy" to the new name followed by a "delete" of the old name. Only the names change, all data relating to the edit history remains the same, and Subversion will still use the old name in older revisions of the "tree". However, Subversion may become confused when files are modified and moved in the same commit. This can also cause problems when a move conflicts with edits made elsewhere, for example during merging branches. The Subversion 1.5 release addressed some of these scenarios while others remain problematic.

As of 2010, Subversion lacks some repository-administration and management features. For instance, someone may wish to edit the repository to permanently remove all historical records of certain data. Subversion does not have built-in support to achieve this simply.

Subversion stores additional copies of data on the local machine, which can become an issue with very large projects or files, or if developers work on multiple branches simultaneously. These .svn directories on the client side can become corrupted by ill-advised user activity.

Subversion does not store the modification times of files. As such, a file checked out of a Subversion repository will have the 'current' date (instead of the modification time in the repository), and a file checked into the repository will have the date of the check-in (instead of the modification time of the file being checked in). This might not always be what is wanted. To mitigate this third-party solutions exist that allow for preserving modification time and other filesystem meta-data. However, giving checked out files a current date is important as well — this is how tools like make(1) will take notice of a changed file for rebuilding it.

Subversion uses a centralized revision control model. Ben Collins-Sussman, one of the designers of Subversion, believes a centralised model would help prevent "insecure programmers" from hiding their work from other team members. Some users of version control systems see the centralised model as detrimental; famously, Linus Torvalds attacked Subversion's model and its developers.

While Subversion stores filenames as Unicode, it does not specify if precomposition or decomposition is used for certain accented characters (such as é). Thus, files added in SVN clients running on some operating systems (such as Mac OS X) use decomposition encoding, while clients running on other operating systems (such as Linux) use precomposition encoding, with the consequence that those accented characters do not display correctly if the local SVN client is not using the same encoding as the client used to add the files.