Assume correct relative or absolute URL from Weblink provider

I you have a change URL like:
http://localhost:8080/c/test-project/+/688
Stepping back to parts "../../" will get you:
http://localhost:8080/c/
Wich is _not_ the base url.
Do not try to guess how URL is constructed but trust WebLink providers
to provide an absolute or a relative URL.

Provide correct relative url from Gitweb.

Bug: Issue 5316
Change-Id: I7f404d470a8fe0f32ef94bb2c7b4c6a9ba68a2b8
(cherry picked from commit 69ab4a8569a690da7d6fc0c57e0a74c2d97ef6c0)

3 files changed, 16 insertions, 7 deletions

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/config/GitwebConfig.java b/gerrit-server/src/main/java/com/google/gerrit/server/config/GitwebConfig.java
index 6c0f7696b7..91eaf3c7d3 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/config/GitwebConfig.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/config/GitwebConfig.java
@@ -35,6 +35,8 @@ import com.google.gerrit.extensions.webui.TagWebLink;
 import com.google.inject.AbstractModule;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
+import java.net.MalformedURLException;
+import java.net.URL;
 import org.eclipse.jgit.lib.Config;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -179,7 +181,11 @@ public class GitwebConfig {
   private final GitwebType type;
 
   @Inject
-  GitwebConfig(GitwebCgiConfig cgiConfig, @GerritServerConfig Config cfg) {
+  GitwebConfig(
+      GitwebCgiConfig cgiConfig,
+      @GerritServerConfig Config cfg,
+      @Nullable @CanonicalWebUrl String gerritUrl)
+      throws MalformedURLException {
     if (isDisabled(cfg)) {
       type = null;
       url = null;
@@ -192,7 +198,14 @@ public class GitwebConfig {
         // Use an externally managed gitweb instance, and not an internal one.
         url = cfgUrl;
       } else {
-        url = firstNonNull(cfgUrl, "gitweb");
+        String baseGerritUrl;
+        if (gerritUrl != null) {
+          URL u = new URL(gerritUrl);
+          baseGerritUrl = u.getPath();
+        } else {
+          baseGerritUrl = "/";
+        }
+        url = firstNonNull(cfgUrl, baseGerritUrl + "gitweb");
       }
     }
   }
diff --git a/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info.js b/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info.js
index 5aa8601dbb..6ccf7466f2 100644
--- a/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info.js
+++ b/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info.js
@@ -81,10 +81,6 @@
         return;
       }
 
-      if (!/^https?\:\/\//.test(webLink)) {
-        webLink = '../../' + webLink;
-      }
-
       return webLink;
     },
 
diff --git a/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info_test.html b/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info_test.html
index c8faff5d64..10a51f619c 100644
--- a/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info_test.html
+++ b/polygerrit-ui/app/elements/change/gr-commit-info/gr-commit-info_test.html
@@ -56,7 +56,7 @@ limitations under the License.
       assert.isOk(element._computeShowWebLink(element.change,
           element.commitInfo, element.serverConfig));
       assert.equal(element._computeWebLink(element.change, element.commitInfo,
-          element.serverConfig), '../../link-url');
+          element.serverConfig), 'link-url');
     });
 
     test('does not relativize web links that begin with scheme', function() {