[log] IDEA-115980 Don't show Git actions if there are no Git roots

platform/vcs-log/api/src/com/intellij/vcs/log/VcsLog.java

@@ -72,4 +72,10 @@ public interface VcsLog {
   @NotNull
   Component getToolbar();
 
+  /**
+   * Returns {@link VcsLogProvider VcsLogProviders} which are active in this log, i.e. which VCS roots are shown in the log.
+   */
+  @NotNull
+  Collection<VcsLogProvider> getLogProviders();
+
 }

platform/vcs-log/impl/src/com/intellij/vcs/log/data/VcsLogDataHolder.java

@@ -491,6 +491,11 @@ public class VcsLogDataHolder implements Disposable {
     return myLogProviders.keySet();
   }
 
+  @NotNull
+  public Collection<VcsLogProvider> getLogProviders() {
+    return myLogProviders.values();
+  }
+
   private static class RecentCommitsInfo {
     List<TimedVcsCommit> firstBlockCommits;
     Collection<VcsRef> newRefs;

platform/vcs-log/impl/src/com/intellij/vcs/log/impl/VcsLogImpl.java

@@ -18,10 +18,7 @@ package com.intellij.vcs.log.impl;
 import com.intellij.openapi.util.Condition;
 import com.intellij.ui.table.JBTable;
 import com.intellij.util.containers.ContainerUtil;
-import com.intellij.vcs.log.Hash;
-import com.intellij.vcs.log.VcsFullCommitDetails;
-import com.intellij.vcs.log.VcsLog;
-import com.intellij.vcs.log.VcsRef;
+import com.intellij.vcs.log.*;
 import com.intellij.vcs.log.data.VcsLogDataHolder;
 import com.intellij.vcs.log.ui.VcsLogUI;
 import com.intellij.vcs.log.ui.tables.AbstractVcsLogTableModel;
@@ -115,4 +112,11 @@ public class VcsLogImpl implements VcsLog {
   public Component getToolbar() {
     return myUi.getToolbar();
   }
+
+  @NotNull
+  @Override
+  public Collection<VcsLogProvider> getLogProviders() {
+    return myDataHolder.getLogProviders();
+  }
+
 }

plugins/git4idea/src/git4idea/GitUtil.java

@@ -23,6 +23,7 @@ import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.progress.ProgressIndicator;
 import com.intellij.openapi.progress.Task;
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.Condition;
 import com.intellij.openapi.util.Pair;
 import com.intellij.openapi.util.io.FileUtil;
 import com.intellij.openapi.util.text.StringUtil;
@@ -37,7 +38,10 @@ import com.intellij.openapi.vfs.LocalFileSystem;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.util.Consumer;
 import com.intellij.util.Function;
+import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.ui.UIUtil;
+import com.intellij.vcs.log.VcsLog;
+import com.intellij.vcs.log.VcsLogProvider;
 import com.intellij.vcsUtil.VcsFileUtil;
 import com.intellij.vcsUtil.VcsUtil;
 import git4idea.branch.GitBranchUtil;
@@ -951,4 +955,16 @@ public class GitUtil {
                            repositoryManager.getRepositories()));
   }
 
+  /**
+   * Checks if there are Git roots in the VCS log.
+   */
+  public static boolean logHasGitRoot(@NotNull VcsLog log) {
+    return ContainerUtil.find(log.getLogProviders(), new Condition<VcsLogProvider>() {
+      @Override
+      public boolean value(VcsLogProvider logProvider) {
+        return logProvider.getSupportedVcs().equals(GitVcs.getKey());
+      }
+    }) != null;
+  }
+
 }

plugins/git4idea/src/git4idea/actions/GitLogSingleCommitAction.java

@@ -83,7 +83,7 @@ public abstract class GitLogSingleCommitAction extends DumbAwareAction {
     }
 
     boolean isValid() {
-      return project != null && log != null;
+      return project != null && log != null && GitUtil.logHasGitRoot(log);
     }
   }
 

plugins/git4idea/src/git4idea/cherrypick/GitCherryPickAction.java

@@ -29,6 +29,7 @@ import com.intellij.util.containers.ContainerUtil;
 import com.intellij.vcs.log.*;
 import git4idea.GitLocalBranch;
 import git4idea.GitPlatformFacade;
+import git4idea.GitUtil;
 import git4idea.GitVcs;
 import git4idea.commands.Git;
 import git4idea.config.GitVcsSettings;
@@ -131,7 +132,13 @@ public class GitCherryPickAction extends DumbAwareAction {
   @Override
   public void update(AnActionEvent e) {
     super.update(e);
-    e.getPresentation().setEnabled(enabled(e));
+    final VcsLog log = getVcsLog(e);
+    if (log != null && !GitUtil.logHasGitRoot(log)) {
+      e.getPresentation().setEnabledAndVisible(false);
+    }
+    else {
+      e.getPresentation().setEnabled(enabled(e));
+    }
   }
 
   private boolean enabled(AnActionEvent e) {