NOTES ON VERSION COMPATIBILITY This file attempts to document the compatibility issues between different Subversion clients and servers. More specifically, where we want to change our (WebDAV) protocol usage in an incomptabile way, and our stepwise plan towards rolling out that change. BINARY PROPERTIES ================= Change: to signify that a property is binary, we will add an attribute onto the property element that specifies its encoding (base64 or standard XML entity escaping). Problem: old clients and servers will not be looking for this attribute, and will not decode the contents appropriately. The current plan from issue 1015: --------------- Okay, I've decided to propagate this functionality in three stages, with a couple of milestones between each stage: (1) server and client learn to recognize and handle the new 'V:encoding' attribute on properties. at this point, no binary properties will actually be coming across the ra-dav wire. (0.20 milestone) (2) server starts to transmit non-XML-safe properties with the 'V:encoding="base64"' attribute and the property value base64-encoded. during this interim period, clients will be to get binary properties from the server, but will not be able to commit new or modified binary properties. (0.21 milestone) (3) clients starts to transmit non-XML-safe properties with the 'V:encoding="base64"' attribute and the property value base64-encoded. this is the moment of full support. (0.22 milestone) All the code for full support will be in place, but disabled functionality will be wrapped in SVN_DAV_FEATURE_BINARY_PROPS #defines. When stage 2 is ready to go into 0.21, we just remove the #defines from the code in mod_dav_svn, commit, and reset this issue to have a 0.24 milestone. When stage 3 is ready to go into 0.22, we just remove the #defines from the code in libsvn_ra_dav, lose the #define itself from svn_dav.h, commit, and close this issue. --------------- REPOSITORY UUIDS ================ Change: Problem: Plan: PROPERTY NAMESPACES =================== Change: Problem: Plan: HANDLING OF UNKNOWN XML ELEMENTS ================================ Change: Problem: Plan: [note: need to review any "else" conditions to ensure we don't fall into them for unknown/future props; some if constructs might have assumed only (say) three elements were possible, so only tested for two of them, and fell to the else for the third]