Restore user dependency precedence over stdlib in classpath (#1369)

User dependencies should take precedence over the Kotlin stdlib to
prevent stdlib classes from shadowing explicit user dependencies.
This restores the ordering behavior from 2.1.7 while preserving the
associates feature added in 2.1.8.

Fixes #1368

Author: agluszak

kotlin/internal/jvm/jvm_deps.bzl

@@ -29,10 +29,10 @@ def _jvm_deps(ctx, toolchains, associate_deps, deps = [], deps_java_infos = [],
         associates = associate_deps,
     )
     dep_infos = (
-        [toolchains.kt.jvm_stdlibs] +
-        associates.dep_infos +
         deps_java_infos +
-        [_java_info(d) for d in deps]
+        [_java_info(d) for d in deps] +
+        associates.dep_infos +
+        [toolchains.kt.jvm_stdlibs]
     )
 
     # Reduced classpath, exclude transitive deps from compilation

src/test/starlark/internal/jvm/jvm_deps_tests.bzl

@@ -266,6 +266,113 @@ def _transitive_from_exports_test(name):
 def _transitive_from_associates_test(name):
     _abi_test(name, _transitive_from_associates_test_impl)
 
+def _dep_infos_ordering_test_impl(env, target):
+    """Test that user deps take precedence over stdlib in dep_infos ordering.
+
+    This is a regression test for https://github.com/bazelbuild/rules_kotlin/issues/1368
+    where the stdlib was placed first in the classpath, causing it to shadow user
+    dependencies with conflicting classes (e.g., org.jetbrains.annotations.NotNull).
+    """
+    user_dep_java_info = JavaInfo(
+        compile_jar = _file(env.ctx.attr.user_dep_jar),
+        output_jar = _file(env.ctx.attr.user_dep_jar),
+    )
+
+    associate_java_info = JavaInfo(
+        compile_jar = _file(env.ctx.attr.associate_jar),
+        output_jar = _file(env.ctx.attr.associate_jar),
+    )
+
+    stdlib_java_info = JavaInfo(
+        compile_jar = _file(env.ctx.attr.jvm_jar),
+        output_jar = _file(env.ctx.attr.jvm_jar),
+    )
+
+    associate_deps = [
+        {
+            JavaInfo: associate_java_info,
+            _KtJvmInfo: _KtJvmInfo(
+                module_name = "associate_name",
+            ),
+        },
+    ]
+
+    user_deps = [
+        {
+            JavaInfo: user_dep_java_info,
+        },
+    ]
+
+    fake_ctx = struct(
+        label = target.label,
+        attr = struct(
+            module_name = "",
+            tags = [],
+        ),
+    )
+
+    toolchains = struct(
+        kt = struct(
+            experimental_remove_private_classes_in_abi_jars = False,
+            experimental_prune_transitive_deps = False,
+            experimental_strict_associate_dependencies = False,
+            jvm_stdlibs = stdlib_java_info,
+        ),
+    )
+
+    result = _jvm_deps_utils.jvm_deps(
+        ctx = fake_ctx,
+        toolchains = toolchains,
+        associate_deps = associate_deps,
+        deps = user_deps,
+    )
+
+    # Assert the ordering: result.deps should be [user_deps, associates, stdlib]
+    env.expect.that_int(len(result.deps)).equals(3)
+
+    # Verify compile_jars contains all deps in correct order
+    classpath_list = result.compile_jars.to_list()
+    user_dep_file = _file(env.ctx.attr.user_dep_jar)
+    stdlib_file = _file(env.ctx.attr.jvm_jar)
+
+    # Find indices of user dep and stdlib in classpath
+    user_dep_idx = -1
+    stdlib_idx = -1
+    for idx, jar in enumerate(classpath_list):
+        if jar == user_dep_file:
+            user_dep_idx = idx
+        if jar == stdlib_file:
+            stdlib_idx = idx
+
+    # Both should be found
+    env.expect.that_bool(user_dep_idx >= 0).equals(True)
+    env.expect.that_bool(stdlib_idx >= 0).equals(True)
+
+    # User dep should come before stdlib in the classpath
+    env.expect.that_bool(user_dep_idx < stdlib_idx).equals(True)
+
+def _dep_infos_ordering_test(name):
+    util.helper_target(
+        native.filegroup,
+        name = name + "_subject",
+        srcs = [],
+    )
+    analysis_test(
+        name = name,
+        impl = _dep_infos_ordering_test_impl,
+        target = name + "_subject",
+        attr_values = {
+            "user_dep_jar": util.empty_file(name + "user_dep.jar"),
+            "associate_jar": util.empty_file(name + "associate.jar"),
+            "jvm_jar": util.empty_file(name + "jvm.jar"),
+        },
+        attrs = {
+            "user_dep_jar": attr.label(allow_files = True),
+            "associate_jar": attr.label(allow_files = True),
+            "jvm_jar": attr.label(allow_files = True),
+        },
+    )
+
 def jvm_deps_test_suite(name):
     test_suite(
         name,
@@ -274,5 +381,6 @@ def jvm_deps_test_suite(name):
             _fat_abi_test,
             _transitive_from_exports_test,
             _transitive_from_associates_test,
+            _dep_infos_ordering_test,
         ],
     )