From 5a1b9bb5cf894b1fc0da2cb6dac1b1cc2cd664e2 Mon Sep 17 00:00:00 2001
From: John DiSanti <jdisanti@amazon.com>
Date: Tue, 10 Aug 2021 16:47:07 -0700
Subject: [PATCH 1/2] Fix name collision in generated union functions

---
 codegen-test/build.gradle.kts                 |  8 ++-
 ...ithy => naming-obstacle-course-ops.smithy} |  0
 .../naming-obstacle-course-structs.smithy     | 53 +++++++++++++++++++
 .../smithy/generators/UnionGenerator.kt       |  2 +-
 4 files changed, 61 insertions(+), 2 deletions(-)
 rename codegen-test/model/{naming-obstacle-course.smithy => naming-obstacle-course-ops.smithy} (100%)
 create mode 100644 codegen-test/model/naming-obstacle-course-structs.smithy

diff --git a/codegen-test/build.gradle.kts b/codegen-test/build.gradle.kts
index f815edecacd..91909f8ca74 100644
--- a/codegen-test/build.gradle.kts
+++ b/codegen-test/build.gradle.kts
@@ -61,7 +61,13 @@ val CodegenTests = listOf(
     ),
     CodegenTest(
         "crate#Config",
-        "naming_test", """
+        "naming_test_ops", """
+            , "codegen": { "renameErrors": false }
+        """.trimIndent()
+    ),
+    CodegenTest(
+        "naming_obs_structs#NamingObstacleCourseStructs",
+        "naming_test_structs", """
             , "codegen": { "renameErrors": false }
         """.trimIndent()
     )
diff --git a/codegen-test/model/naming-obstacle-course.smithy b/codegen-test/model/naming-obstacle-course-ops.smithy
similarity index 100%
rename from codegen-test/model/naming-obstacle-course.smithy
rename to codegen-test/model/naming-obstacle-course-ops.smithy
diff --git a/codegen-test/model/naming-obstacle-course-structs.smithy b/codegen-test/model/naming-obstacle-course-structs.smithy
new file mode 100644
index 00000000000..7b40c352ddb
--- /dev/null
+++ b/codegen-test/model/naming-obstacle-course-structs.smithy
@@ -0,0 +1,53 @@
+$version: "1.0"
+namespace naming_obs_structs
+
+use aws.protocols#awsJson1_1
+use aws.api#service
+
+/// Confounds model generation machinery with lots of problematic names
+@awsJson1_1
+@service(sdkId: "NamingObstacleCourseStructs")
+service NamingObstacleCourseStructs {
+    version: "2006-03-01",
+    operations: [
+       Structs,
+    ]
+}
+
+structure SomethingElse {
+    result: Result,
+    resultList: ResultList,
+    option: Option,
+    optionList: OptionList,
+    someUnion: SomeUnion,
+}
+
+union SomeUnion {
+    Result: Result,
+    Option: Option,
+}
+
+structure Result {
+    value: String,
+}
+list ResultList {
+    member: Result,
+}
+structure Option {
+    value: String,
+}
+list OptionList {
+    member: Result,
+}
+
+structure StructsInputOutput {
+    result: Result,
+    resultList: ResultList,
+    option: Option,
+    optionList: OptionList,
+    somethingElse: SomethingElse,
+}
+operation Structs {
+    input: StructsInputOutput,
+    output: StructsInputOutput
+}
diff --git a/codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/generators/UnionGenerator.kt b/codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/generators/UnionGenerator.kt
index 000ed558e92..1337d56eea4 100644
--- a/codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/generators/UnionGenerator.kt
+++ b/codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/generators/UnionGenerator.kt
@@ -51,7 +51,7 @@ class UnionGenerator(
                 if (sortedMembers.size == 1) {
                     Attribute.Custom("allow(irrefutable_let_patterns)").render(this)
                 }
-                rustBlock("pub fn as_$funcNamePart(&self) -> Result<&#T, &Self>", memberSymbol) {
+                rustBlock("pub fn as_$funcNamePart(&self) -> std::result::Result<&#T, &Self>", memberSymbol) {
                     rust("if let ${unionSymbol.name}::$variantName(val) = &self { Ok(&val) } else { Err(&self) }")
                 }
                 rustBlock("pub fn is_$funcNamePart(&self) -> bool") {

From 74c61816ebe3b965b4332bd78830eb2a8db67a07 Mon Sep 17 00:00:00 2001
From: John DiSanti <jdisanti@amazon.com>
Date: Tue, 10 Aug 2021 16:58:00 -0700
Subject: [PATCH 2/2] Update the CHANGELOG

---
 CHANGELOG.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3736ba2060b..5414a9486d8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,9 @@
 vNext (Month Day, Year)
 -----------------------
+
+**New This Week**
 - (When complete) Add profile file provider for region (#594, #xyz)
+- :bug: Fix name collision that occurred when a model had both a union and a structure named `Result` (#643)
 
 v0.20 (August 10th, 2021)
 --------------------------