Fix new_http_archive's strip_prefix for zips

The removal of the prefix was incorrectly applied to the zip entry
instead of the destination.

Fixes #221

Tested:
    - Added a copy of the existing integration test with zip archive
    - bash compile.sh all

--
Change-Id: I5d5f75f66a17eb6f146afafb1f347a781490e616
Reviewed-on: https://bazel-review.googlesource.com/#/c/2084/
MOS_MIGRATED_REVID=104774296

src/main/java/com/google/devtools/build/lib/bazel/repository/ZipFunction.java

@@ -73,8 +73,7 @@ public SkyValue compute(SkyKey skyKey, Environment env) throws RepositoryFunctio
         if (entryPath.skip()) {
           continue;
         }
-        entry.setName(entryPath.getPathFragment().getPathString());
-        extractZipEntry(reader, entry, destinationDirectory);
+        extractZipEntry(reader, entry, destinationDirectory, entryPath.getPathFragment());
       }
     } catch (IOException e) {
       throw new RepositoryFunctionException(new IOException(
@@ -92,16 +91,19 @@ public SkyValue compute(SkyKey skyKey, Environment env) throws RepositoryFunctio
     return new DecompressorValue(destinationDirectory);
   }
 
-  private void extractZipEntry(ZipReader reader, ZipFileEntry entry, Path destinationDirectory)
+  private void extractZipEntry(
+      ZipReader reader,
+      ZipFileEntry entry,
+      Path destinationDirectory,
+      PathFragment strippedRelativePath)
       throws IOException {
-    String relativeString = entry.getName();
-    PathFragment relativePath = new PathFragment(relativeString);
-    if (relativePath.isAbsolute()) {
+    if (strippedRelativePath.isAbsolute()) {
       throw new IOException(
-          String.format("Failed to extract %s, zipped paths cannot be absolute", relativePath));
+          String.format(
+              "Failed to extract %s, zipped paths cannot be absolute", strippedRelativePath));
     }
-    Path outputPath = destinationDirectory.getRelative(relativePath);
-    int permissions = getPermissions(entry.getExternalAttributes(), relativeString);
+    Path outputPath = destinationDirectory.getRelative(strippedRelativePath);
+    int permissions = getPermissions(entry.getExternalAttributes(), entry.getName());
     FileSystemUtils.createDirectoryAndParents(outputPath.getParentDirectory());
     boolean isDirectory = (permissions & 040000) == 040000;
     if (isDirectory) {

src/test/shell/bazel/external_integration_test.sh

@@ -500,7 +500,7 @@ EOF
   expect_log "bazel fetch //..."
 }
 
-function test_prefix_stripping() {
+function test_prefix_stripping_tar_gz() {
   mkdir -p x/y/z
   echo "abc" > x/y/z/w
   tar czf x.tar.gz x
@@ -529,4 +529,33 @@ EOF
   assert_contains "abc" bazel-genfiles/external/x/catter.out
 }
 
+function test_prefix_stripping_zip() {
+  mkdir -p x/y/z
+  echo "abc" > x/y/z/w
+  zip -r x x
+  local sha256=$(sha256sum x.zip | cut -f 1 -d ' ')
+  serve_file x.zip
+
+  cat > WORKSPACE <<EOF
+new_http_archive(
+    name = "x",
+    url = "http://localhost:$nc_port/x.zip",
+    sha256 = "$sha256",
+    strip_prefix = "x/y/z",
+    build_file = "x.BUILD",
+)
+EOF
+  cat > x.BUILD <<EOF
+genrule(
+    name = "catter",
+    cmd = "cat \$< > \$@",
+    outs = ["catter.out"],
+    srcs = ["w"],
+)
+EOF
+
+  bazel build @x//:catter &> $TEST_log || fail "Build failed"
+  assert_contains "abc" bazel-genfiles/external/x/catter.out
+}
+
 run_suite "external tests"