Commit 733b2082565a86daac6f2b22a1a27f0b60621b4e | zig

author	Andrew Kelley <andrew@ziglang.org> 2025-07-25 14:14:40-07:00
committer	Andrew Kelley <andrew@ziglang.org> 2025-07-25 14:15:33-07:00
log	733b2082565a86daac6f2b22a1a27f0b60621b4e
tree	fc42c2ab6477bf021ee79e37dcc8707eb22ea185
parent	8752d80c8444249ff6b62e40f918bf53b4bad2b8

std.posix.ftruncate: handle NonResizable properly

2 files changed, 7 insertions(+), 3 deletions(-)

lib
- std
  - fs
    File.zig
  - posix.zig

lib/std/fs/File.zig+4-1

 @@ -2029,7 +2029,10 @@ pub const Writer = struct {
         switch (w.mode) {
             .positional,
             .positional_reading,
-            => try w.file.setEndPos(w.pos),
+            => w.file.setEndPos(w.pos) catch |err| switch (err) {
+                error.NonResizable => return,
+                else => |e| return e,
+            },
             .streaming,
             .streaming_reading,

lib/std/posix.zig+3-2

...	@@ -1052,6 +1052,7 @@ pub const TruncateError = error{	...	@@ -1052,6 +1052,7 @@ pub const TruncateError = error{
1052	FileBusy,	1052	FileBusy,
1053	AccessDenied,	1053	AccessDenied,
1054	PermissionDenied,	1054	PermissionDenied,
		1055	NonResizable,
1055	} \|\| UnexpectedError;	1056	} \|\| UnexpectedError;
1056		1057
1057	/// Length must be positive when treated as an i64.	1058	/// Length must be positive when treated as an i64.
...	@@ -1091,7 +1092,7 @@ pub fn ftruncate(fd: fd_t, length: u64) TruncateError!void {	...	@@ -1091,7 +1092,7 @@ pub fn ftruncate(fd: fd_t, length: u64) TruncateError!void {
1091	.PERM => return error.PermissionDenied,	1092	.PERM => return error.PermissionDenied,
1092	.TXTBSY => return error.FileBusy,	1093	.TXTBSY => return error.FileBusy,
1093	.BADF => unreachable, // Handle not open for writing	1094	.BADF => unreachable, // Handle not open for writing
1094	.INVAL => unreachable, // Handle not open for writing, negative length, or non-resizable handle	1095	.INVAL => return error.NonResizable,
1095	.NOTCAPABLE => return error.AccessDenied,	1096	.NOTCAPABLE => return error.AccessDenied,
1096	else => \|err\| return unexpectedErrno(err),	1097	else => \|err\| return unexpectedErrno(err),
1097	}	1098	}
...	@@ -1107,7 +1108,7 @@ pub fn ftruncate(fd: fd_t, length: u64) TruncateError!void {	...	@@ -1107,7 +1108,7 @@ pub fn ftruncate(fd: fd_t, length: u64) TruncateError!void {
1107	.PERM => return error.PermissionDenied,	1108	.PERM => return error.PermissionDenied,
1108	.TXTBSY => return error.FileBusy,	1109	.TXTBSY => return error.FileBusy,
1109	.BADF => unreachable, // Handle not open for writing	1110	.BADF => unreachable, // Handle not open for writing
1110	.INVAL => unreachable, // Handle not open for writing, negative length, or non-resizable handle	1111	.INVAL => return error.NonResizable, // This is returned for /dev/null for example.
1111	else => \|err\| return unexpectedErrno(err),	1112	else => \|err\| return unexpectedErrno(err),
1112	}	1113	}
1113	}	1114	}