added handling of duplicated values

Author: torfjelde

src/varinfo.jl

@@ -683,8 +683,11 @@ function vector_getranges(varinfo::TypedVarInfo, vns::Vector{<:VarName})
         for vn in vns_metadata
             r_vn = getrange(metadata, vn)
             # Get the index, so we return in the same order as `vns`.
-            idx = findfirst(==(vn), vns)
-            ranges[idx] = r_vn .+ offset
+            # NOTE: There might be duplicates in `vns`, so we need to handle that.
+            indices = findall(==(vn), vns)
+            for idx in indices
+                ranges[idx] = r_vn .+ offset
+            end
         end
     end
     # Raise key error if any of the variables were not found.

test/varinfo.jl

@@ -849,6 +849,9 @@ DynamicPPL.getspace(::DynamicPPL.Sampler{MySAlg}) = (:s,)
                 @test_throws KeyError DynamicPPL.vector_getranges(
                     varinfo, [VarName{gensym("vn")}(), VarName{gensym("vn")}()]
                 )
+                # Duplicate variables.
+                ranges_duplicated = DynamicPPL.vector_getranges(varinfo, repeat(vns, 2))
+                @test x[reduce(vcat, ranges_duplicated)] == repeat(x, 2)
             end
         end
     end