Clarify limitations in project list filters

Update the documentation to clarify:

- Regex and prefix filters are case sensitive
- Substring filter is case insensitive
- Regex, prefix and substring may not be used together

Add tests for case [in]sensitivity.

Change-Id: I5de7f5f43b6ecc55dd15c4c009e2e11bd7e72567

Documentation/rest-api-projects.txt

@@ -149,6 +149,8 @@ Prefix(p)::
 Limit the results to those projects that start with the specified
 prefix.
 +
+The match is case sensitive. May not be used together with `m` or `r`.
++
 List all projects that start with `platform/`:
 +
 .Request
@@ -182,6 +184,8 @@ Boundary matchers '^' and '$' are implicit. For example: the regex 'test.*' will
 match any projects that start with 'test' and regex '.*test' will match any
 project that end with 'test'.
 +
+The match is case sensitive. May not be used together with `m` or `p`.
++
 List all projects that match regex `test.*project`:
 +
 .Request
@@ -234,6 +238,8 @@ Query the second project in the project list:
 Substring(m)::
 Limit the results to those projects that match the specified substring.
 +
+The match is case insensitive. May not be used together with `r` or `p`.
++
 List all projects that match substring `test/`:
 +
 .Request

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/project/ListProjectsIT.java

@@ -112,6 +112,8 @@ public class ListProjectsIT extends AbstractDaemonTest {
     assertThatNameList(filter(gApi.projects().list().withPrefix(p).get()))
         .containsExactly(someOtherProject, someProject)
         .inOrder();
+    p = name("SOME");
+    assertThatNameList(filter(gApi.projects().list().withPrefix(p).get())).isEmpty();
   }
 
   @Test
@@ -161,6 +163,9 @@ public class ListProjectsIT extends AbstractDaemonTest {
     assertThatNameList(filter(gApi.projects().list().withSubstring("some").get()))
         .containsExactly(projectAwesome, someOtherProject, someProject)
         .inOrder();
+    assertThatNameList(filter(gApi.projects().list().withSubstring("SOME").get()))
+        .containsExactly(projectAwesome, someOtherProject, someProject)
+        .inOrder();
   }
 
   @Test