Allow adding prefix path when unpacking HTTP repos.

Motivation: #16136

Closes #16137.

PiperOrigin-RevId: 469410562
Change-Id: Iab57783de006604bab9dde268cd2225310f2dab6

Author: inazarenko

src/test/shell/bazel/external_integration_test.sh

@@ -752,6 +752,69 @@ EOF
   assert_contains "abc" bazel-genfiles/external/x/catter.out
 }
 
+function test_adding_prefix_zip() {
+  mkdir -p z
+  echo "abc" > z/w
+  zip -r z z
+  local sha256=$(sha256sum z.zip | cut -f 1 -d ' ')
+  serve_file z.zip
+
+  cat >> $(create_workspace_with_default_repos WORKSPACE) <<EOF
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+http_archive(
+    name = "ws",
+    url = "http://127.0.0.1:$nc_port/z.zip",
+    sha256 = "$sha256",
+    add_prefix = "x/y",
+    build_file = "@//:ws.BUILD",
+)
+EOF
+  cat > ws.BUILD <<EOF
+genrule(
+    name = "catter",
+    cmd = "cat \$< > \$@",
+    outs = ["catter.out"],
+    srcs = ["x/y/z/w"],
+)
+EOF
+  touch BUILD
+
+  bazel build @ws//:catter &> $TEST_log || fail "Build failed"
+  assert_contains "abc" bazel-genfiles/external/ws/catter.out
+}
+
+function test_adding_and_stripping_prefix_zip() {
+  mkdir -p z
+  echo "abc" > z/w
+  zip -r z z
+  local sha256=$(sha256sum z.zip | cut -f 1 -d ' ')
+  serve_file z.zip
+
+  cat >> $(create_workspace_with_default_repos WORKSPACE) <<EOF
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+http_archive(
+    name = "ws",
+    url = "http://127.0.0.1:$nc_port/z.zip",
+    sha256 = "$sha256",
+    strip_prefix = "z",
+    add_prefix = "x",
+    build_file = "@//:ws.BUILD",
+)
+EOF
+  cat > ws.BUILD <<EOF
+genrule(
+    name = "catter",
+    cmd = "cat \$< > \$@",
+    outs = ["catter.out"],
+    srcs = ["x/w"],
+)
+EOF
+  touch BUILD
+
+  bazel build @ws//:catter &> $TEST_log || fail "Build failed"
+  assert_contains "abc" bazel-genfiles/external/ws/catter.out
+}
+
 function test_moving_build_file() {
   echo "abc" > w
   tar czf x.tar.gz w

tools/build_defs/repo/http.bzl

@@ -129,7 +129,7 @@ def _http_archive_impl(ctx):
 
     download_info = ctx.download_and_extract(
         all_urls,
-        "",
+        ctx.attr.add_prefix,
         ctx.attr.sha256,
         ctx.attr.type,
         ctx.attr.strip_prefix,
@@ -270,6 +270,15 @@ discarded and inaccessible (e.g., a top-level license file). This includes
 files/directories that start with the prefix but are not in the directory
 (e.g., `foo-lib-1.2.3.release-notes`). If the specified prefix does not
 match a directory in the archive, Bazel will return an error.""",
+    ),
+    "add_prefix": attr.string(
+        default = "",
+        doc = """Destination directory relative to the repository directory.
+
+The archive will be unpacked into this directory, after applying `strip_prefix`
+(if any) to the file paths within the archive. For example, file
+`foo-1.2.3/src/foo.h` will be unpacked to `bar/src/foo.h` if `add_prefix = "bar"`
+and `strip_prefix = "foo-1.2.3"`.""",
     ),
     "type": attr.string(
         doc = """The archive type of the downloaded file.