Merge pull request #1766 from rainersigwald/item-case-sensitivity-1751

Item references should be case-insensitive

Author: rainersigwald

src/XMakeBuildEngine/Evaluation/LazyItemEvaluator.cs

@@ -49,7 +49,13 @@ internal partial class LazyItemEvaluator<P, I, M, D>
         /// </summary>
         private static CompareInfo s_invariantCompareInfo = CultureInfo.InvariantCulture.CompareInfo;
 
-        private Dictionary<string, LazyItemList> _itemLists = new Dictionary<string, LazyItemList>();
+        // MSBUILDUSECASESENSITIVEITEMNAMES is an escape hatch for the fix
+        // for https://github.com/Microsoft/msbuild/issues/1751. It should
+        // be removed (permanently set to false) after establishing that
+        // it's unneeded (at least by the 16.0 timeframe).
+        private Dictionary<string, LazyItemList> _itemLists = Environment.GetEnvironmentVariable("MSBUILDUSECASESENSITIVEITEMNAMES") == "1" ?
+            new Dictionary<string, LazyItemList>() :
+            new Dictionary<string, LazyItemList>(MSBuildNameIgnoreCaseComparer.Default);
 
         public LazyItemEvaluator(IEvaluatorData<P, I, M, D> data, IItemFactory<I, I> itemFactory, BuildEventContext buildEventContext, ILoggingService loggingService)
         {
@@ -365,7 +371,10 @@ private class OperationBuilder
             public string ItemType { get; set; }
             public ItemSpec<P,I> ItemSpec { get; set; }
 
-            public ImmutableDictionary<string, LazyItemList>.Builder ReferencedItemLists { get; } = ImmutableDictionary.CreateBuilder<string, LazyItemList>();
+            public ImmutableDictionary<string, LazyItemList>.Builder ReferencedItemLists { get; } = Environment.GetEnvironmentVariable("MSBUILDUSECASESENSITIVEITEMNAMES") == "1" ?
+                ImmutableDictionary.CreateBuilder<string, LazyItemList>() :
+                ImmutableDictionary.CreateBuilder<string, LazyItemList>(MSBuildNameIgnoreCaseComparer.Default);
+
             public bool ConditionResult { get; set; }
 
             public OperationBuilder(ProjectItemElement itemElement, bool conditionResult)

src/XMakeBuildEngine/UnitTests/Evaluation/Evaluator_Tests.cs

@@ -1395,6 +1395,68 @@ public void ItemPredecessorToItem()
             Assert.Equal(null, metadatum.Predecessor.Predecessor);
         }
 
+        [Fact]
+        public void ItemPredecessorToItemWithCaseChange()
+        {
+            string content = ObjectModelHelpers.CleanupFileContents(@"
+                    <Project xmlns='msbuildnamespace' >
+                        <ItemGroup>
+                          <item_with_lowercase_name Include='h1'>
+                            <m>1</m>
+                          </item_with_lowercase_name>
+                          <i Include='@(ITEM_WITH_LOWERCASE_NAME)'>
+                            <m>2;%(m)</m>
+                          </i>
+                        </ItemGroup>
+                    </Project>");
+
+            Project project = new Project(XmlReader.Create(new StringReader(content)));
+
+            ProjectMetadataElement metadataElementFromProjectRootElement =
+                project.Xml.Items.First().Metadata.First();
+
+            Assert.Collection(project.GetItems("i"), item =>
+            {
+                ProjectMetadata metadatum = item.GetMetadata("m");
+
+                Assert.Equal("2;1", metadatum.EvaluatedValue);
+                Assert.Equal("1", metadatum.Predecessor.EvaluatedValue);
+                Assert.Same(metadataElementFromProjectRootElement, metadatum.Predecessor.Xml);
+
+                Assert.Null(metadatum.Predecessor.Predecessor);
+            });
+        }
+
+        /// <summary>
+        /// Should be removed when escape hatch for #1751 is removed
+        /// </summary>
+        [Fact]
+        public void ItemPredecessorToItemWithCaseChangeAndEscapeHatch()
+        {
+            using (new Helpers.TemporaryEnvironment("MSBUILDUSECASESENSITIVEITEMNAMES", "1"))
+            {
+                string content = ObjectModelHelpers.CleanupFileContents(@"
+                    <Project xmlns='msbuildnamespace' >
+                        <ItemGroup>
+                          <item_with_lowercase_name Include='h1'>
+                            <m>1</m>
+                          </item_with_lowercase_name>
+                          <i Include='@(ITEM_WITH_LOWERCASE_NAME)'>
+                            <m>2;%(m)</m>
+                          </i>
+                        </ItemGroup>
+                    </Project>");
+
+                Project project = new Project(XmlReader.Create(new StringReader(content)));
+
+                ProjectMetadataElement metadataElementFromProjectRootElement =
+                    project.Xml.Items.First().Metadata.First();
+
+                // empty because of the case mismatch
+                Assert.Collection(project.GetItems("i"));
+            }
+        }
+
         /// <summary>
         /// Predecessor of item is item via transform
         /// </summary>
@@ -1421,6 +1483,58 @@ public void ItemPredecessorToItemViaTransform()
             Assert.Equal(null, metadatum.Predecessor);
         }
 
+        [Fact]
+        public void ItemPredecessorToItemViaTransformWithCaseChange()
+        {
+            string content = ObjectModelHelpers.CleanupFileContents(@"
+                    <Project xmlns='msbuildnamespace' >
+                        <ItemGroup>
+                          <ITEM_WITH_UPPERCASE_NAME Include='h1'>
+                            <m>1</m>
+                          </ITEM_WITH_UPPERCASE_NAME>
+                          <i Include=""@(item_with_uppercase_name->'%(identity)')"">
+                            <m>2;%(m)</m>
+                          </i>
+                        </ItemGroup>
+                    </Project>");
+
+
+            Project project = new Project(XmlReader.Create(new StringReader(content)));
+
+            Assert.Collection(project.GetItems("i"), item =>
+            {
+                Assert.Equal("h1", item.EvaluatedInclude);
+            });
+        }
+
+        /// <summary>
+        /// Should be removed when escape hatch for #1751 is removed
+        /// </summary>
+        [Fact]
+        public void ItemPredecessorToItemViaTransformWithCaseChangeWithEscapeHatch()
+        {
+            using (new Helpers.TemporaryEnvironment("MSBUILDUSECASESENSITIVEITEMNAMES", "1"))
+            {
+                string content = ObjectModelHelpers.CleanupFileContents(@"
+                    <Project xmlns='msbuildnamespace' >
+                        <ItemGroup>
+                          <ITEM_WITH_UPPERCASE_NAME Include='h1'>
+                            <m>1</m>
+                          </ITEM_WITH_UPPERCASE_NAME>
+                          <i Include=""@(item_with_uppercase_name->'%(identity)')"">
+                            <m>2;%(m)</m>
+                          </i>
+                        </ItemGroup>
+                    </Project>");
+
+
+                Project project = new Project(XmlReader.Create(new StringReader(content)));
+
+                // Should be empty because of the case mismatch
+                Assert.Collection(project.GetItems("i"));
+            }
+        }
+
         /// <summary>
         /// Item predecessors and imports
         /// </summary>