Allow partially valid results returned from find command when listi…

…ng files and directories (#2311)

* Minor fix for the temporary directory for on-disk cache

If and only if the $TMPDIR env is not set should we try to fallback to
/tmp as the temporary directory for on-disk cache files.

* Do not return nil if `find` returns error when listing dir/files on remote ssh device

`find` command may partially succeed, in which case we should process
the successfully listed items and ignore the error messages. This CL
redirect the errors generated by `find` to /dev/null to strip away error
messages.

core/os/device/remotessh/commands.go

@@ -321,10 +321,9 @@ func (b binding) ListExecutables(ctx context.Context, inPath string) ([]string,
 	if inPath == "" {
 		inPath = b.GetURIRoot()
 	}
-	files, err := b.Shell("find", `"`+inPath+`"`, "-mindepth", "1", "-maxdepth", "1", "-type", "f", "-executable", "-printf", `%f\\n`).Call(ctx)
-	if err != nil {
-		return nil, err
-	}
+	// 'find' may partially succeed. Redirect the error messages to /dev/null,
+	// only process the successfully found executables.
+	files, _ := b.Shell("find", `"`+inPath+`"`, "-mindepth", "1", "-maxdepth", "1", "-type", "f", "-executable", "-printf", `%f\\n`, "2>/dev/null").Call(ctx)
 	scanner := bufio.NewScanner(strings.NewReader(files))
 	out := []string{}
 	for scanner.Scan() {
@@ -339,10 +338,9 @@ func (b binding) ListDirectories(ctx context.Context, inPath string) ([]string,
 	if inPath == "" {
 		inPath = b.GetURIRoot()
 	}
-	dirs, err := b.Shell("find", `"`+inPath+`"`, "-mindepth", "1", "-maxdepth", "1", "-type", "d", "-printf", `%f\\n`).Call(ctx)
-	if err != nil {
-		return nil, err
-	}
+	// 'find' may partially succeed. Redirect the error messages to /dev/null,
+	// only process the successfully found directories.
+	dirs, _ := b.Shell("find", `"`+inPath+`"`, "-mindepth", "1", "-maxdepth", "1", "-type", "d", "-printf", `%f\\n`, "2>/dev/null").Call(ctx)
 	scanner := bufio.NewScanner(strings.NewReader(dirs))
 	out := []string{}
 	for scanner.Scan() {