Detect missing paths in hg fileview command

If a not existing path is request in the fileview command, it will
be treated as an empty directory. But such a thing does not exist in hg.
Therefore we handle this result as what it is: a not existing path -
and we throw a not found exception.

CHANGELOG.md

@@ -1,3 +1,4 @@
+
 # Changelog
 All notable changes to this project will be documented in this file.
 
@@ -17,6 +18,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Overflow for too long branch names ([#1339](https://github.com/scm-manager/scm-manager/pull/1339))
 - Set default branch in branch selector if nothing is selected ([#1338](https://github.com/scm-manager/scm-manager/pull/1338))
 - Handling of branch with slashes in source view ([#1340](https://github.com/scm-manager/scm-manager/pull/1340))
+- Detect not existing paths correctly in Mercurial ([#1343](https://github.com/scm-manager/scm-manager/pull/1343))
 
 ## [2.5.0] - 2020-09-10
 ### Added

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/HgBrowseCommand.java

@@ -36,6 +36,9 @@ import sonia.scm.repository.spi.javahg.HgFileviewCommand;
 
 import java.io.IOException;
 
+import static sonia.scm.ContextEntry.ContextBuilder.entity;
+import static sonia.scm.NotFoundException.notFound;
+
 //~--- JDK imports ------------------------------------------------------------
 
 /**
@@ -93,7 +96,8 @@ public class HgBrowseCommand extends AbstractCommand implements BrowseCommand
     cmd.setLimit(request.getLimit());
     cmd.setOffset(request.getOffset());
 
-    FileObject file = cmd.execute();
+    FileObject file = cmd.execute()
+      .orElseThrow(() -> notFound(entity("File", request.getPath()).in("Revision", revision).in(getRepository())));
     return new BrowserResult(c == null? "tip": c.getNode(), revision, file);
   }
 }

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/javahg/HgFileviewCommand.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.repository.spi.javahg;
 
 //~--- non-JDK imports --------------------------------------------------------
@@ -29,12 +29,12 @@ package sonia.scm.repository.spi.javahg;
 import com.aragost.javahg.Repository;
 import com.aragost.javahg.internals.AbstractCommand;
 import com.aragost.javahg.internals.HgInputStream;
-
 import sonia.scm.repository.FileObject;
 
 //~--- JDK imports ------------------------------------------------------------
 
 import java.io.IOException;
+import java.util.Optional;
 
 /**
  * Mercurial command to list files of a repository.
@@ -161,7 +161,7 @@ public class HgFileviewCommand extends AbstractCommand
    *
    * @throws IOException
    */
-  public FileObject execute() throws IOException
+  public Optional<FileObject> execute() throws IOException
   {
     cmdAppend("-t");
 

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/javahg/HgFileviewCommandResultReader.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.repository.spi.javahg;
 
 import com.aragost.javahg.DateTime;
@@ -35,6 +35,10 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Deque;
 import java.util.LinkedList;
+import java.util.Optional;
+
+import static java.util.Optional.empty;
+import static java.util.Optional.of;
 
 class HgFileviewCommandResultReader {
 
@@ -48,7 +52,7 @@ class HgFileviewCommandResultReader {
     this.disableLastCommit = disableLastCommit;
   }
 
-  FileObject parseResult() throws IOException {
+  Optional<FileObject> parseResult() throws IOException {
     Deque<FileObject> stack = new LinkedList<>();
 
     FileObject last = null;
@@ -82,13 +86,17 @@ class HgFileviewCommandResultReader {
 
     if (stack.isEmpty()) {
       // if the stack is empty, the requested path is probably a file
-      return last;
+      return of(last);
+    } else if (stack.size() == 1 && stack.getFirst().isDirectory() && stack.getFirst().getChildren().isEmpty()) {
+      // There are no empty directories in hg. When we get this,
+      // we just get the requested path as a directory, but it does not exist.
+      return empty();
     } else {
       // if the stack is not empty, the requested path is a directory
       if (stream.read() == TRUNCATED_MARK) {
         stack.getLast().setTruncated(true);
       }
-      return stack.getLast();
+      return of(stack.getLast());
     }
   }
 

scm-plugins/scm-hg-plugin/src/test/java/sonia/scm/repository/spi/javahg/HgFileviewCommandResultReaderTest.java

@@ -21,11 +21,10 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.repository.spi.javahg;
 
 import com.aragost.javahg.internals.HgInputStream;
-import org.assertj.core.api.Assertions;
 import org.junit.jupiter.api.Test;
 import sonia.scm.repository.FileObject;
 
@@ -34,6 +33,7 @@ import java.io.IOException;
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;
 import java.util.Iterator;
+import java.util.Optional;
 import java.util.OptionalLong;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
@@ -55,7 +55,7 @@ class HgFileviewCommandResultReaderTest {
       .file("b.txt", 100, time2.toEpochMilli(), "file b\nwith some\nmore text")
       .build();
 
-    FileObject fileObject = reader.parseResult();
+    FileObject fileObject = reader.parseResult().get();
 
     assertThat(fileObject.isDirectory()).isTrue();
     assertThat(fileObject.getChildren())
@@ -84,7 +84,7 @@ class HgFileviewCommandResultReaderTest {
       .file("a.txt")
       .truncated();
 
-    FileObject fileObject = reader.parseResult();
+    FileObject fileObject = reader.parseResult().get();
 
     assertThat(fileObject.isTruncated()).isTrue();
   }
@@ -96,7 +96,7 @@ class HgFileviewCommandResultReaderTest {
       .file("dir/a.txt")
       .build();
 
-    FileObject fileObject = reader.parseResult();
+    FileObject fileObject = reader.parseResult().get();
 
     assertThat(fileObject.isDirectory()).isTrue();
     assertThat(fileObject.getName()).isEqualTo("dir");
@@ -117,7 +117,7 @@ class HgFileviewCommandResultReaderTest {
       .file("d.txt")
       .build();
 
-    FileObject fileObject = reader.parseResult();
+    FileObject fileObject = reader.parseResult().get();
 
     assertThat(fileObject.getChildren())
       .extracting("name")
@@ -152,7 +152,7 @@ class HgFileviewCommandResultReaderTest {
       .file("d.txt")
       .build();
 
-    FileObject fileObject = reader.parseResult();
+    FileObject fileObject = reader.parseResult().get();
 
     assertThat(fileObject.getChildren())
       .extracting("name")
@@ -179,7 +179,7 @@ class HgFileviewCommandResultReaderTest {
       .file("d.txt")
       .build();
 
-    FileObject fileObject = reader.parseResult();
+    FileObject fileObject = reader.parseResult().get();
 
     assertThat(fileObject.getChildren())
       .extracting("name")
@@ -213,7 +213,7 @@ class HgFileviewCommandResultReaderTest {
       .file("directory/b.txt")
       .build();
 
-    FileObject fileObject = reader.parseResult();
+    FileObject fileObject = reader.parseResult().get();
 
     assertThat(fileObject.getChildren())
       .extracting("name")
@@ -248,7 +248,7 @@ class HgFileviewCommandResultReaderTest {
       .file("a.txt")
       .build();
 
-    FileObject fileObject = reader.parseResult();
+    FileObject fileObject = reader.parseResult().get();
 
     assertThat(fileObject.getChildren())
       .extracting("description")
@@ -258,6 +258,17 @@ class HgFileviewCommandResultReaderTest {
       .containsOnly(OptionalLong.empty());
   }
 
+  @Test
+  void shouldIgnoreSingleEmptyDir() throws IOException {
+    HgFileviewCommandResultReader reader = new MockInput()
+      .dir("empty")
+      .build();
+
+    Optional<FileObject> fileObject = reader.parseResult();
+
+    assertThat(fileObject).isEmpty();
+  }
+
   private HgInputStream createInputStream(String input) {
     return new HgInputStream(new ByteArrayInputStream(input.getBytes(UTF_8)), UTF_8.newDecoder());
   }