docs/config: document inverted matches cancel each others
Our config had two inverted matches to exclude projects:
[remote "github"]
projects = ^(?:(?!apps\\/android\\/).)*$
projects = ^(?:(?!apps\\/ios\\/).)*$
I have been wondering why `apps/android/wikipedia` is excluded given it
matches the first regex. The reason is ReplicationFilter applies each
pattern and when one matches it accepts the project. In this case, the
project is matched by the second and is thus accepted.
Ref: https://phabricator.wikimedia.org/T392198
Change-Id: I2846a40d2aabe80c0db305dc4f64dd1aa885b07d
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index bb4be9a..b5c4b36 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -546,10 +546,13 @@
they do in Gerrit.
<a name="remote.NAME.projects">remote.NAME.projects</a>
-: Specifies which repositories should be replicated to the
- remote. It can be provided more than once, and supports three
- formats: regular expressions, wildcard matching, and single
- project matching. All three formats match case-sensitive.
+: Specifies which repositories should be replicated to the remote. It
+ can be provided more than once, if any matches, the repository will
+ be replicated.
+
+ Projects supports three formats: regular expressions, wildcard
+ matching, and single project matching. All three formats match
+ case-sensitive.
Values starting with a caret `^` are treated as regular
expressions. `^foo/(bar|baz)` would match the projects
@@ -559,7 +562,12 @@
Projects may be excluded from replication by using a regular
expression with inverse match. `^(?:(?!PATTERN).)*$` will
- exclude any project that matches.
+ exclude any project that matches. Beware: if another project pattern
+ matches the project, it will be replicated. You can not provide
+ multiple inverted matches since they will cancel each other (a
+ project `foo` would not be matched by `^(?:(?!foo).)*$` but would be
+ matched if a second inverted match `^(?:(?!bar).)*$` is also provided
+ since it matches `foo`).
Values that are not regular expressions and end in `*` are
treated as wildcard matches. Wildcards match projects whose
