On 28.06.2018 22:08, Julian Foad wrote: > Philip Martin wrote: >> Julian Foad <julianf...@apache.org> writes: >>> Julian Foad wrote: >>>> The bug seems to be that 'svn patch' fails to apply any patch of >>>> this form, that tries to change a property value from empty to >>>> non-empty. >>> I committed a test for this in http://svn.apache.org/r1834628 >> I'm confused, you are treating as '' special? Suppose an existing >> property P has value 'foo'. Should a patch that adds P with value 'bar' > The issue is about a patch that *changes* the current value to another value, > not a patch that *adds* a property. > > I am pointing out that a patch that changes the empty value '' to 'bar' > should be (and isn't being) applied successfully to a property that already > has the empty value ''. > > The patch format for modifying an empty value is mostly the same as the patch > format for adding a new property: > > [[[ > Property changes on: f > ___________________________________________________________________ > Added: empty > ## -0,0 +1 ## > +foo > \ No newline at end of property > ]]] > vs. > [[[ > Property changes on: f > ___________________________________________________________________ > Modified: empty > ## -0,0 +1 ## > +foo > \ No newline at end of property > ]]] > > It's similar to the ambiguous patch representation of create a file or add > text to an empty file. In that case, 'svn patch' first creates the file if it > doesn't exist, and in both scenarios adds the patch text. > > For a property patch, a property-patch header line specifies whether it's a > modify or an add, so there is no ambiguity. If the patch asks to 'modify' > from empty to non-empty, when the target property already exists and has an > empty value, this should certainly succeed.
However, when libsvn_client creates the svn:executable property, it *always* sets its value to *. Applying a patch from empty to something else will then very likely result in a conflict; because the svn:executable property value cannot be empty (unless someone used a broken client). This has been true since at least version 0.14., some 15 years ago. -- Brane
