Backport prepare_for_deletion() (#38159)

Author: staticfloat

base/file.jl

@@ -458,6 +458,32 @@ function tempdir()
     end
 end
 
+"""
+    prepare_for_deletion(path::AbstractString)
+
+Prepares the given `path` for deletion by ensuring that all directories within that
+`path` have write permissions, so that files can be removed from them.  This is
+automatically invoked by methods such as `mktempdir()` to ensure that no matter what
+weird permissions a user may have created directories with within the temporary prefix,
+it will always be deleted.
+"""
+function prepare_for_deletion(path::AbstractString)
+    # Nothing to do for non-directories
+    if !isdir(path)
+        return
+    end
+
+    try chmod(path, filemode(path) | 0o333)
+    catch; end
+    for (root, dirs, files) in walkdir(path)
+        for dir in dirs
+            dpath = joinpath(root, dir)
+            try chmod(dpath, filemode(dpath) | 0o333)
+            catch; end
+        end
+    end
+end
+
 const TEMP_CLEANUP_MIN = Ref(1024)
 const TEMP_CLEANUP_MAX = Ref(1024)
 const TEMP_CLEANUP = Dict{String,Bool}()
@@ -484,6 +510,7 @@ function temp_cleanup_purge(all::Bool=true)
             if (all || asap) && ispath(path)
                 need_gc && GC.gc(true)
                 need_gc = false
+                prepare_for_deletion(path)
                 rm(path, recursive=true, force=true)
             end
             !ispath(path) && delete!(TEMP_CLEANUP, path)
@@ -682,7 +709,10 @@ function mktempdir(fn::Function, parent::AbstractString=tempdir();
         fn(tmpdir)
     finally
         try
-            ispath(tmpdir) && rm(tmpdir, recursive=true)
+            if ispath(tmpdir)
+                prepare_for_deletion(tmpdir)
+                rm(tmpdir, recursive=true)
+            end
         catch ex
             @error "mktempdir cleanup" _group=:file exception=(ex, catch_backtrace())
             # might be possible to remove later

test/file.jl

@@ -268,6 +268,20 @@ no_error_logging(f::Function) =
     end
 end
 
+@testset "mktempdir() permissions correction" begin
+    # Test that `mktempdir()` with children with weird permissions get cleared
+    # before we would delete the directory
+    local temp_dir_path
+    mktempdir() do dir
+        temp_dir_path = dir
+        mkdir(joinpath(dir, "foo"))
+        touch(joinpath(dir, "foo", "bar"))
+        chmod(joinpath(dir, "foo"), 0o444)
+        @test isdir(temp_dir_path)
+    end
+    @test !isdir(temp_dir_path)
+end
+
 #######################################################################
 # This section tests some of the features of the stat-based file info #
 #######################################################################