From efa4edfadb3d8ac051ac21ccb4238f3eadb091dd Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Wed, 18 Sep 2019 04:21:19 -0700 Subject: [PATCH] Be less picky about EACCES in file test predicates Problem reported by Tino Calancha (Bug#37445) and others. * src/fileio.c (PICKY_EACCES): New constant, false by default. (file_test_errno): Ignore EACCES if not picky. (check_file_access): Investigate EACCES problems further if picky. --- src/fileio.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/src/fileio.c b/src/fileio.c index 0977516f01..58bc6b7ee8 100644 --- a/src/fileio.c +++ b/src/fileio.c @@ -253,9 +253,23 @@ file_attribute_errno (Lisp_Object file, int err) return file_metadata_errno ("Getting attributes", file, err); } +/* In theory, EACCES errors for predicates like file-readable-p should + be checked further because they may be problems with an ancestor + directory instead of with the file itself, which means that we + don't have reliable info about the requested file. In practice, + though, such errors are common enough that signaling them can be + annoying even if the errors are real (e.g., Bug#37445). So return + nil for EACCES unless compiling with -DPICKY_EACCES, which is off + by default. */ +#ifndef PICKY_EACCES +enum { PICKY_EACCES = false }; +#endif + static Lisp_Object file_test_errno (Lisp_Object file, int err) { + if (!PICKY_EACCES && err == EACCES) + return Qnil; return file_metadata_errno ("Testing file", file, err); } @@ -2745,7 +2759,7 @@ check_file_access (Lisp_Object file, Lisp_Object operation, int amode) return Qt; int err = errno; if (err == EROFS || err == ETXTBSY - || (err == EACCES && amode != F_OK + || (PICKY_EACCES && err == EACCES && amode != F_OK && file_access_p (encoded_file, F_OK))) { errno = err; -- 2.17.1