Merge pull request #246 from GunnarFarneback/fix_merge_tag

Allow duplicate keys when merge tags are used.

Author: kescobo

.github/workflows/ci.yml

@@ -19,32 +19,23 @@ jobs:
         os:
           - ubuntu-latest
           - windows-latest
-          - macOS-latest
+          - macOS-13
         arch:
           - x64
           - x86
         exclude:
-          - os: macOS-latest
+          - os: macOS-13
             arch: x86
     steps:
-      - uses: actions/checkout@v2
-      - uses: julia-actions/setup-julia@v1
+      - uses: actions/checkout@v4
+      - uses: julia-actions/setup-julia@v2
         with:
           version: ${{ matrix.version }}
           arch: ${{ matrix.arch }}
-      - uses: actions/cache@v1
-        env:
-          cache-name: cache-artifacts
-        with:
-          path: ~/.julia/artifacts
-          key: ${{ runner.os }}-test-${{ env.cache-name }}-${{ hashFiles('**/Project.toml') }}
-          restore-keys: |
-            ${{ runner.os }}-test-${{ env.cache-name }}-
-            ${{ runner.os }}-test-
-            ${{ runner.os }}-
+      - uses: julia-actions/cache@v2
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
       - uses: julia-actions/julia-processcoverage@v1
-      - uses: codecov/codecov-action@v1
+      - uses: codecov/codecov-action@v5
         with:
-          file: lcov.info
+          files: lcov.info

Project.toml

@@ -1,6 +1,6 @@
 name = "YAML"
 uuid = "ddb6d928-2868-570f-bddf-ab3f9cf99eb6"
-version = "0.4.13"
+version = "0.4.14"
 
 
 [deps]

src/constructor.jl

@@ -135,6 +135,7 @@ function construct_sequence(constructor::Constructor, node::Node)
 end
 
 
+# Returns true if a merge tag was used and false otherwise.
 function flatten_mapping(node::MappingNode)
     merge = []
     index = 1
@@ -171,12 +172,22 @@ function flatten_mapping(node::MappingNode)
 
     if !isempty(merge)
         node.value = vcat(merge, node.value)
+        return true
     end
+
+    return false
 end
 
 
 function construct_mapping(dicttype::Union{Type,Function}, constructor::Constructor, node::MappingNode; strict_unique_keys::Bool=false)
-    flatten_mapping(node)
+    # If the mapping was constructed with a merge tag, skip the later
+    # test for duplicates, since it is a key part of the merging
+    # functionality that selected values can be changed.
+    #
+    # (Ideally uniqueness would still be tested for the keys outside
+    # of the merge tags, but that would require more intricate changes
+    # to the code.)
+    merged_mapping = flatten_mapping(node)
     mapping = dicttype()
     for (key_node, value_node) in node.value
         key = construct_object(constructor, key_node)
@@ -191,7 +202,7 @@ function construct_mapping(dicttype::Union{Type,Function}, constructor::Construc
             end
         end
         try
-            if haskey(mapping, key)
+            if !merged_mapping && haskey(mapping, key)
                 strict_unique_keys ? error("Duplicate key `$(key)` detected in mapping.") : @error "Duplicate key detected in mapping" node key
             end
             mapping[key] = value