Make sure commands suggested in REPL shell mode are unique

Often binaries are in the env path more than once, but
we obviously only want to suggest them once to the user.

Author: mariushoch

base/REPLCompletions.jl

@@ -133,12 +133,12 @@ function complete_path(path::AbstractString, pos; use_envpath=false)
         return UTF8String[], 0:-1, false
     end
 
-    matches = UTF8String[]
+    matches = Dict{UTF8String,Bool}()
     for file in files
         if startswith(file, prefix)
             id = try isdir(joinpath(dir, file)) catch; false end
             # joinpath is not used because windows needs to complete with double-backslash
-            push!(matches, id ? file * (@windows? "\\\\" : "/") : file)
+            matches[id ? file * (@windows? "\\\\" : "/") : file] = true
         end
     end
 
@@ -178,18 +178,18 @@ function complete_path(path::AbstractString, pos; use_envpath=false)
                 # In a perfect world, we would filter on whether the file is executable
                 # here, or even on whether the current user can execute the file in question.
                 if startswith(file, prefix) && isfile(joinpath(pathdir, file))
-                    push!(matches, file)
+                    matches[file] = true
                 end
             end
         end
     end
 
-    matches = UTF8String[replace(s, r"\s", "\\ ") for s in matches]
+    matchList = UTF8String[replace(s, r"\s", "\\ ") for s in keys(matches)]
     startpos = pos - endof(prefix) + 1 - length(matchall(r" ", prefix))
     # The pos - endof(prefix) + 1 is correct due to `endof(prefix)-endof(prefix)==0`,
     # hence we need to add one to get the first index. This is also correct when considering
     # pos, because pos is the `endof` a larger string which `endswith(path)==true`.
-    return matches, startpos:pos, !isempty(matches)
+    return matchList, startpos:pos, !isempty(matchList)
 end
 
 # Determines whether method_complete should be tried. It should only be done if

test/replcompletions.jl

@@ -434,7 +434,6 @@ c, r, res = test_scomplete(s)
     # Pressing tab after having entered "/tmp " should not
     # attempt to complete "/tmp" but rather work on the current
     # working directory again.
-
     let
         file = joinpath(path, "repl completions")
         s = "/tmp "
@@ -494,6 +493,31 @@ c, r, res = test_scomplete(s)
         ENV["PATH"] = oldpath
     end
 
+    # Make sure completion results are unique in case things are in the env path twice.
+    let
+        file0 = joinpath(tempdir(), "repl-completion")
+        dir = joinpath(tempdir(), "repl-completion-subdir")
+        file1 = joinpath(dir, "repl-completion")
+
+        try
+            # Create /tmp/repl-completion and /tmp/repl-completion-subdir/repl-completion
+            mkdir(dir)
+            touch(file0)
+            touch(file1)
+
+            withenv("PATH" => string(tempdir(), ":", dir)) do
+                s = string("repl-completio")
+                c,r = test_scomplete(s)
+                @test [utf8("repl-completion")] == c
+                @test s[r] == "repl-completio"
+            end
+
+        finally
+            rm(file0)
+            rm(file1)
+            rm(dir)
+        end
+    end
 end
 
 let #test that it can auto complete with spaces in file/path