windows accepts '\\' and '/' as path separators

Author: fatteneder

base/loading.jl

@@ -3123,6 +3123,9 @@ mutable struct CacheHeaderIncludes
 end
 
 function replace_depot_path(path::AbstractString)
+    @static if Sys.iswindows()
+        path = replace(path, Filesystem.path_separator_re=>Filesystem.pathsep())
+    end
     for depot in DEPOT_PATH
         !isdir(depot) && continue
 
@@ -3131,6 +3134,10 @@ function replace_depot_path(path::AbstractString)
             depot = dirname(depot)
         end
 
+        @static if Sys.iswindows()
+            depot = replace(depot, Filesystem.path_separator_re=>Filesystem.pathsep())
+        end
+
         if startswith(path, string(depot, Filesystem.pathsep())) || path == depot
             path = replace(path, depot => "@depot"; count=1)
             break

test/relocatedepot.jl

@@ -70,6 +70,21 @@ if !test_relocated_depot
                 @test Base.replace_depot_path(jlrc) != "@depot-rc2"
                 @test Base.replace_depot_path(jlrc) == jlrc
             end
+            if Sys.iswindows()
+                # windows accepts '\\' and '/' as path separators
+                mktempdir() do dir
+                    jlrc = string(dir, "/", "julia-rc2")
+                    jl   = string(dir, "/", "julia")
+                    mkdir(jl)
+                    push!(DEPOT_PATH, jl)
+                    @test Base.replace_depot_path(jl) == "@depot"
+                    @test Base.replace_depot_path(string(jl,"/"))  == string("@depot","\\")
+                    @test Base.replace_depot_path(string(jl,"\\")) == string("@depot","\\")
+                    @test Base.replace_depot_path(jlrc) != "@depot-rc2"
+                    @test Base.replace_depot_path(jlrc) ==
+                        replace(jlrc, Base.Filesystem.path_separator_re=>"\\")
+                end
+            end
         end
 
     end