From dca48fe8d7f86e49dad856bad1e970b837912793 Mon Sep 17 00:00:00 2001
From: Saugat Pachhai <suagatchhetri@outlook.com>
Date: Sat, 7 Nov 2020 09:30:12 +0545
Subject: [PATCH] Skip loading globally used params section again locally for
 stages (#4859)

We were still trying to load params file used in `use`
for local stages which was throwing overwrite error.
Thanks to @dmpetrov for pointing out.
---
 dvc/parsing/__init__.py           | 19 +++++++----
 tests/func/test_stage_resolver.py | 53 +++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/dvc/parsing/__init__.py b/dvc/parsing/__init__.py
index fecc209b1..92e96d151 100644
--- a/dvc/parsing/__init__.py
+++ b/dvc/parsing/__init__.py
@@ -89,12 +89,19 @@ class DataResolver:
                     "%s does not exist for stage %s", params_yaml_file, name
                 )
 
-        params_file = definition.get(PARAMS_KWD, [])
-        for item in params_file:
-            if item and isinstance(item, dict):
-                contexts.append(
-                    Context.load_from(self.repo.tree, str(wdir / first(item)))
-                )
+        params_deps = definition.get(PARAMS_KWD, [])
+        params_files = {
+            wdir / first(item)
+            for item in params_deps
+            if item and isinstance(item, dict)
+        }
+        for params_file in params_files - {
+            self.global_ctx_source,
+            params_yaml_file,
+        }:
+            contexts.append(
+                Context.load_from(self.repo.tree, str(params_file))
+            )
 
         context.merge_update(*contexts)
 
diff --git a/tests/func/test_stage_resolver.py b/tests/func/test_stage_resolver.py
index 28e4c6e12..0a000e863 100644
--- a/tests/func/test_stage_resolver.py
+++ b/tests/func/test_stage_resolver.py
@@ -429,3 +429,56 @@ def test_set_with_foreach_and_on_stage_definition(tmp_dir, dvc):
             }
         },
     )
+
+
+def test_resolve_local_tries_to_load_globally_used_files(tmp_dir, dvc):
+    iterable = {"bar": "bar", "foo": "foo"}
+    dump_json(tmp_dir / "params.json", iterable)
+
+    d = {
+        "use": "params.json",
+        "stages": {
+            "build": {
+                "cmd": "command --value ${bar}",
+                "params": [{"params.json": ["foo"]}],
+            },
+        },
+    }
+    resolver = DataResolver(dvc, PathInfo(str(tmp_dir)), d)
+    assert_stage_equal(
+        resolver.resolve(),
+        {
+            "stages": {
+                "build": {
+                    "cmd": "command --value bar",
+                    "params": [{"params.json": ["bar", "foo"]}],
+                },
+            }
+        },
+    )
+
+
+def test_resolve_local_tries_to_load_globally_used_params_yaml(tmp_dir, dvc):
+    iterable = {"bar": "bar", "foo": "foo"}
+    dump_yaml(tmp_dir / "params.yaml", iterable)
+
+    d = {
+        "stages": {
+            "build": {
+                "cmd": "command --value ${bar}",
+                "params": [{"params.yaml": ["foo"]}],
+            },
+        },
+    }
+    resolver = DataResolver(dvc, PathInfo(str(tmp_dir)), d)
+    assert_stage_equal(
+        resolver.resolve(),
+        {
+            "stages": {
+                "build": {
+                    "cmd": "command --value bar",
+                    "params": [{"params.yaml": ["bar", "foo"]}],
+                },
+            }
+        },
+    )