IDEA-89754 Add a pre-commit check on core.autocrlf option and warn if CRLF is about to be committed to the repository. Step #1.

* Add another check to the GitCheckinHandler (windows only).
* Add the option to disable the check to the settings (visible for windows only).
* Add the dialog warning about CRLFs: GitCrlfDialog
* Declare the actual GitCrlfProblemsDetector - just as a stub now.

plugins/git4idea/src/git4idea/checkin/GitCheckinHandlerFactory.java

@@ -19,6 +19,7 @@ import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.ui.Messages;
 import com.intellij.openapi.util.Pair;
+import com.intellij.openapi.util.SystemInfo;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vcs.CheckinProjectPanel;
 import com.intellij.openapi.vcs.ProjectLevelVcsManager;
@@ -28,11 +29,15 @@ import com.intellij.openapi.vcs.checkin.CheckinHandler;
 import com.intellij.openapi.vcs.checkin.VcsCheckinHandlerFactory;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.util.PairConsumer;
+import com.intellij.util.ui.UIUtil;
 import git4idea.GitUtil;
 import git4idea.GitVcs;
 import git4idea.config.GitConfigUtil;
+import git4idea.config.GitVcsSettings;
 import git4idea.config.GitVersion;
 import git4idea.config.GitVersionSpecialty;
+import git4idea.crlf.GitCrlfDialog;
+import git4idea.crlf.GitCrlfProblemsDetector;
 import git4idea.i18n.GitBundle;
 import git4idea.repo.GitRepository;
 import git4idea.repo.GitRepositoryManager;
@@ -60,10 +65,13 @@ public class GitCheckinHandlerFactory extends VcsCheckinHandlerFactory {
   }
 
   private class MyCheckinHandler extends CheckinHandler {
-    private CheckinProjectPanel myPanel;
+    @NotNull private final CheckinProjectPanel myPanel;
+    @NotNull private final Project myProject;
 
-    public MyCheckinHandler(CheckinProjectPanel panel) {
+
+    public MyCheckinHandler(@NotNull CheckinProjectPanel panel) {
       myPanel = panel;
+      myProject = myPanel.getProject();
     }
 
     @Override
@@ -77,11 +85,61 @@ public class GitCheckinHandlerFactory extends VcsCheckinHandlerFactory {
         if (result != ReturnResult.COMMIT) {
           return result;
         }
+        result = warnAboutCrlfIfNeeded();
+        if (result != ReturnResult.COMMIT) {
+          return result;
+        }
         return warnAboutDetachedHeadIfNeeded();
       }
       return ReturnResult.COMMIT;
     }
 
+    @NotNull
+    private ReturnResult warnAboutCrlfIfNeeded() {
+      GitVcsSettings settings = GitVcsSettings.getInstance(myProject);
+      if (!SystemInfo.isWindows || !settings.warnAboutCrlf()) {
+        return ReturnResult.COMMIT;
+      }
+
+      GitCrlfProblemsDetector crlfHelper = GitCrlfProblemsDetector.detect(myPanel.getVirtualFiles());
+      if (crlfHelper.shouldWarn()) {
+        final GitCrlfDialog dialog = new GitCrlfDialog(myProject);
+        UIUtil.invokeAndWaitIfNeeded(new Runnable() {
+          @Override
+          public void run() {
+            dialog.show();
+          }
+        });
+        int decision = dialog.getExitCode();
+        if  (decision == GitCrlfDialog.CANCEL) {
+          return ReturnResult.CANCEL;
+        }
+        else {
+          if (decision == GitCrlfDialog.SET) {
+            VirtualFile anyRoot = myPanel.getRoots().iterator().next(); // config will be set globally => any root will do.
+            setCoreAutoCrlfAttribute(anyRoot);
+          }
+          else {
+            if (dialog.dontWarnAgain()) {
+              settings.setWarnAboutCrlf(false);
+            }
+          }
+          return ReturnResult.COMMIT;
+        }
+      }
+      return ReturnResult.COMMIT;
+    }
+
+    private void setCoreAutoCrlfAttribute(@NotNull VirtualFile aRoot) {
+      try {
+        GitConfigUtil.setValue(myProject, aRoot, GitConfigUtil.CORE_AUTOCRLF, "true", "--global");
+      }
+      catch (VcsException e) {
+        // it is not critical: the user just will get the dialog again next time
+        LOG.warn("Couldn't globally set core.autocrlf in " + aRoot, e);
+      }
+    }
+
     private ReturnResult checkUserName() {
       Project project = myPanel.getProject();
       GitVcs vcs = GitVcs.getInstance(project);

plugins/git4idea/src/git4idea/config/GitConfigUtil.java

@@ -34,13 +34,12 @@ import java.util.Map;
  * Git utilities for working with configuration
  */
 public class GitConfigUtil {
+
   public static final String USER_NAME = "user.name";
   public static final String USER_EMAIL = "user.email";
   public static final String BRANCH_AUTOSETUP_REBASE = "branch.autosetuprebase";
+  public static final String CORE_AUTOCRLF = "core.autocrlf";
 
-  /**
-   * A private constructor for utility class
-   */
   private GitConfigUtil() {
   }
 

plugins/git4idea/src/git4idea/config/GitVcsPanel.form

@@ -91,7 +91,7 @@
           <grid row="2" column="0" row-span="1" col-span="1" vsize-policy="6" hsize-policy="1" anchor="0" fill="2" indent="0" use-parent-layout="false"/>
         </constraints>
       </vspacer>
-      <grid id="4d15a" layout-manager="GridLayoutManager" row-count="3" column-count="1" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
+      <grid id="4d15a" layout-manager="GridLayoutManager" row-count="4" column-count="1" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
         <margin top="0" left="0" bottom="0" right="0"/>
         <constraints>
           <grid row="1" column="0" row-span="1" col-span="1" vsize-policy="3" hsize-policy="3" anchor="0" fill="3" indent="0" use-parent-layout="false"/>
@@ -126,6 +126,14 @@
               <text value="Commit automatically on cherry-pick"/>
             </properties>
           </component>
+          <component id="1ad55" class="com.intellij.ui.components.JBCheckBox" binding="myWarnAboutCrlf" default-binding="true">
+            <constraints>
+              <grid row="3" column="0" row-span="1" col-span="1" vsize-policy="0" hsize-policy="0" anchor="8" fill="0" indent="0" use-parent-layout="false"/>
+            </constraints>
+            <properties>
+              <text value="Warn if &amp;CRLF line separators are about to be committed"/>
+            </properties>
+          </component>
         </children>
       </grid>
     </children>

plugins/git4idea/src/git4idea/config/GitVcsPanel.java

@@ -21,6 +21,7 @@ import com.intellij.openapi.fileChooser.FileChooserDescriptorFactory;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.ui.Messages;
 import com.intellij.openapi.ui.TextFieldWithBrowseButton;
+import com.intellij.openapi.util.SystemInfo;
 import com.intellij.ui.components.JBCheckBox;
 import git4idea.GitVcs;
 import git4idea.i18n.GitBundle;
@@ -39,11 +40,7 @@ public class GitVcsPanel {
 
   private static final String IDEA_SSH = GitBundle.getString("git.vcs.config.ssh.mode.idea"); // IDEA ssh value
   private static final String NATIVE_SSH = GitBundle.getString("git.vcs.config.ssh.mode.native"); // Native SSH value
-  private static final String CRLF_CONVERT_TO_PROJECT = GitBundle.getString("git.vcs.config.convert.project");
-  private static final String CRLF_DO_NOT_CONVERT = GitBundle.getString("git.vcs.config.convert.do.not.convert");
-  private static final String CRLF_ASK = GitBundle.getString("git.vcs.config.convert.ask");
 
-  private final Project myProject;
   private final GitVcsApplicationSettings myAppSettings;
   private final GitVcs myVcs;
 
@@ -54,11 +51,11 @@ public class GitVcsPanel {
   private JCheckBox myAutoUpdateIfPushRejected;
   private JBCheckBox mySyncBranchControl;
   private JCheckBox myAutoCommitOnCherryPick;
+  private JBCheckBox myWarnAboutCrlf;
 
   public GitVcsPanel(@NotNull Project project) {
     myVcs = GitVcs.getInstance(project);
     myAppSettings = GitVcsApplicationSettings.getInstance();
-    myProject = project;
     mySSHExecutableComboBox.addItem(IDEA_SSH);
     mySSHExecutableComboBox.addItem(NATIVE_SSH);
     mySSHExecutableComboBox.setSelectedItem(IDEA_SSH);
@@ -71,8 +68,9 @@ public class GitVcsPanel {
     });
     myGitField.addBrowseFolderListener(GitBundle.getString("find.git.title"), GitBundle.getString("find.git.description"), project,
                                        FileChooserDescriptorFactory.createSingleFileNoJarsDescriptor());
-    final GitRepositoryManager repositoryManager = ServiceManager.getService(myProject, GitRepositoryManager.class);
+    final GitRepositoryManager repositoryManager = ServiceManager.getService(project, GitRepositoryManager.class);
     mySyncBranchControl.setVisible(repositoryManager != null && repositoryManager.moreThanOneRoot());
+    myWarnAboutCrlf.setVisible(SystemInfo.isWindows);
   }
 
   /**
@@ -124,6 +122,7 @@ public class GitVcsPanel {
     myAutoUpdateIfPushRejected.setSelected(settings.autoUpdateIfPushRejected());
     mySyncBranchControl.setSelected(settings.getSyncSetting() == GitBranchSyncSetting.SYNC);
     myAutoCommitOnCherryPick.setSelected(settings.isAutoCommitOnCherryPick());
+    myWarnAboutCrlf.setSelected(settings.warnAboutCrlf());
   }
 
   /**
@@ -136,7 +135,8 @@ public class GitVcsPanel {
            (settings.isIdeaSsh() != IDEA_SSH.equals(mySSHExecutableComboBox.getSelectedItem())) ||
            !settings.autoUpdateIfPushRejected() == myAutoUpdateIfPushRejected.isSelected() ||
            ((settings.getSyncSetting() == GitBranchSyncSetting.SYNC) != mySyncBranchControl.isSelected() ||
-           settings.isAutoCommitOnCherryPick() != myAutoCommitOnCherryPick.isSelected());
+           settings.isAutoCommitOnCherryPick() != myAutoCommitOnCherryPick.isSelected() ||
+           settings.warnAboutCrlf() != myWarnAboutCrlf.isSelected());
   }
 
   /**
@@ -154,5 +154,7 @@ public class GitVcsPanel {
 
     settings.setSyncSetting(mySyncBranchControl.isSelected() ? GitBranchSyncSetting.SYNC : GitBranchSyncSetting.DONT);
     settings.setAutoCommitOnCherryPick(myAutoCommitOnCherryPick.isSelected());
+    settings.setWarnAboutCrlf(myWarnAboutCrlf.isSelected());
   }
+
 }

plugins/git4idea/src/git4idea/config/GitVcsSettings.java

@@ -41,7 +41,7 @@ public class GitVcsSettings implements PersistentStateComponent<GitVcsSettings.S
 
   private final GitVcsApplicationSettings myAppSettings;
   private State myState = new State();
-  
+
   /**
    * The way the local changes are saved before update if user has selected auto-stash
    */
@@ -63,6 +63,7 @@ public class GitVcsSettings implements PersistentStateComponent<GitVcsSettings.S
     public Map<String, String> RECENT_BRANCH_BY_REPOSITORY = new HashMap<String, String>();
     public String RECENT_COMMON_BRANCH = null;
     public boolean AUTO_COMMIT_ON_CHERRY_PICK = false;
+    public boolean WARN_ABOUT_CRLF = true;
   }
 
   public GitVcsSettings(GitVcsApplicationSettings appSettings) {
@@ -171,6 +172,14 @@ public class GitVcsSettings implements PersistentStateComponent<GitVcsSettings.S
     return myState.AUTO_COMMIT_ON_CHERRY_PICK;
   }
 
+  public boolean warnAboutCrlf() {
+    return myState.WARN_ABOUT_CRLF;
+  }
+
+  public void setWarnAboutCrlf(boolean warn) {
+    myState.WARN_ABOUT_CRLF = warn;
+  }
+
   /**
    * Provides migration from project settings.
    * This method is to be removed in IDEA 13: it should be moved to {@link GitVcsApplicationSettings}

plugins/git4idea/src/git4idea/crlf/GitCrlfDialog.java

@@ -0,0 +1,106 @@
+/*
+ * Copyright 2000-2012 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package git4idea.crlf;
+
+import com.intellij.ide.BrowserUtil;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.ui.DialogWrapper;
+import com.intellij.ui.components.JBCheckBox;
+import com.intellij.ui.components.JBLabel;
+import com.intellij.ui.components.labels.LinkLabel;
+import com.intellij.ui.components.labels.LinkListener;
+import com.intellij.util.ui.GridBag;
+import com.intellij.util.ui.UIUtil;
+import org.jetbrains.annotations.Nullable;
+
+import javax.swing.*;
+import java.awt.*;
+
+import static com.intellij.util.ui.UIUtil.DEFAULT_HGAP;
+import static com.intellij.util.ui.UIUtil.DEFAULT_VGAP;
+
+/**
+ * Warns the user that CRLF line separators are about to be committed to the repository.
+ * Provides some additional information and proposes to set {@code git config --global core.autocrlf true}.
+ *
+ * @author Kirill Likhodedov
+ * @see GitCrlfProblemsDetector
+ */
+public class GitCrlfDialog extends DialogWrapper {
+
+  public static final int SET = DialogWrapper.OK_EXIT_CODE;
+  public static final int DONT_SET = DialogWrapper.NEXT_USER_EXIT_CODE;
+  public static final int CANCEL = DialogWrapper.CANCEL_EXIT_CODE;
+  private JBCheckBox myDontWarn;
+
+  public GitCrlfDialog(@Nullable Project project) {
+    super(project, false);
+
+    setOKButtonText("Fix and Commit");
+    setCancelButtonText("Cancel");
+    setTitle("Line separators warning");
+    getCancelAction().putValue(DialogWrapper.FOCUSED_ACTION, true);
+
+    init();
+  }
+
+  @Override
+  protected Action[] createActions() {
+    return new Action[] { getOKAction(), getCancelAction(), new DialogWrapperExitAction("Commit as Is", DONT_SET) };
+  }
+
+  @Override
+  protected JComponent createCenterPanel() {
+    JLabel description = new JBLabel(
+      "<html>You are about to commit CRLF line separators to the Git repository.<br/>" +
+      "It is recommended to set core.autocrlf Git attribute to <code>true</code> to avoid line separator issues.</html>");
+
+    JLabel additionalDescription = new JBLabel(
+      "<html>Fix and Commit: <code>git config --global core.autocrlf true</code> will be called,<br/>" +
+      "Commit as Is: the config value won't be set.</html>", UIUtil.ComponentStyle.SMALL);
+
+    JLabel readMore = new LinkLabel("Read more", null, new LinkListener() {
+      @Override
+      public void linkSelected(LinkLabel aSource, Object aLinkData) {
+        BrowserUtil.launchBrowser("https://help.github.com/articles/dealing-with-line-endings");
+      }
+    });
+
+    JLabel icon = new JLabel(UIUtil.getWarningIcon(), SwingConstants.LEFT);
+    myDontWarn = new JBCheckBox("Don't warn again");
+    myDontWarn.setMnemonic('w');
+
+    JPanel rootPanel = new JPanel(new GridBagLayout());
+    GridBag g = new GridBag()
+      .setDefaultInsets(new Insets(0, 6, DEFAULT_VGAP, DEFAULT_HGAP))
+      .setDefaultAnchor(GridBagConstraints.LINE_START)
+      .setDefaultFill(GridBagConstraints.HORIZONTAL);
+
+    rootPanel.add(icon, g.nextLine().next().coverColumn(4));
+    rootPanel.add(description, g.next());
+    rootPanel.add(readMore, g.nextLine().next().next());
+    rootPanel.add(additionalDescription, g.nextLine().next().next().pady(DEFAULT_HGAP));
+    rootPanel.add(myDontWarn,  g.nextLine().next().next().insets(0, 0, 0, 0));
+
+    return rootPanel;
+
+  }
+
+  public boolean dontWarnAgain() {
+    return myDontWarn.isSelected();
+  }
+
+}

plugins/git4idea/src/git4idea/crlf/GitCrlfProblemsDetector.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2000-2012 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package git4idea.crlf;
+
+import com.intellij.openapi.vfs.VirtualFile;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Collection;
+
+/**
+ * Given a number of files, detects if CRLF line separators in them are about to be committed to Git. That is:
+ * <ul>
+ *   <li>Checks if {@code core.autocrlf} is set to {@code true} or {@code input}.</li>
+ *   <li>If not, checks if files contain CRLFs.</li>
+ *   <li>
+ *     For files with CRLFs checks if there are gitattributes set on them, such that would either force CRLF conversion on checkin,
+ *     either indicate that these CRLFs are here intentionally.
+ *   </li>
+ * </ul>
+ * All checks are made only for Windows system.
+ *
+ * @author Kirill Likhodedov
+ */
+public class GitCrlfProblemsDetector {
+
+  @NotNull
+  public static GitCrlfProblemsDetector detect(Collection<VirtualFile> files) {
+    return new GitCrlfProblemsDetector();
+  }
+
+  public boolean shouldWarn() {
+    return false;
+  }
+
+}