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Skip empty strings in std.fs.path.join function

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Austin Clements 2021-07-26 16:03:30 -05:00 committed by Veikka Tuominen
parent a8e8927c49
commit eb010ce65d
1 changed files with 37 additions and 11 deletions
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48
lib/std/fs/path.zig
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@ -43,17 +43,32 @@ pub fn isSep(byte: u8) bool {
fn joinSepMaybeZ(allocator: *Allocator, separator: u8, sepPredicate: fn (u8) bool, paths: []const []const u8, zero: bool) ![]u8 {
if (paths.len == 0) return if (zero) try allocator.dupe(u8, &[1]u8{0}) else &[0]u8{};
// Find first non-empty path index.
const first_path_index = blk: {
for (paths) |path, index| {
if (path.len == 0) continue else break :blk index;
}
// All paths provided were empty, so return early.
return if (zero) try allocator.dupe(u8, &[1]u8{0}) else &[0]u8{};
};
// Calculate length needed for resulting joined path buffer.
const total_len = blk: {
var sum: usize = paths[0].len;
var i: usize = 1;
var sum: usize = paths[first_path_index].len;
var prev_path = paths[first_path_index];
assert(prev_path.len > 0);
var i: usize = first_path_index + 1;
while (i < paths.len) : (i += 1) {
const prev_path = paths[i - 1];
const this_path = paths[i];
const prev_sep = (prev_path.len != 0 and sepPredicate(prev_path[prev_path.len - 1]));
const this_sep = (this_path.len != 0 and sepPredicate(this_path[0]));
if (this_path.len == 0) continue;
const prev_sep = sepPredicate(prev_path[prev_path.len - 1]);
const this_sep = sepPredicate(this_path[0]);
sum += @boolToInt(!prev_sep and !this_sep);
sum += if (prev_sep and this_sep) this_path.len - 1 else this_path.len;
prev_path = this_path;
}
if (zero) sum += 1;
break :blk sum;
};
@ -61,14 +76,16 @@ fn joinSepMaybeZ(allocator: *Allocator, separator: u8, sepPredicate: fn (u8) boo
const buf = try allocator.alloc(u8, total_len);
errdefer allocator.free(buf);
mem.copy(u8, buf, paths[0]);
var buf_index: usize = paths[0].len;
var i: usize = 1;
mem.copy(u8, buf, paths[first_path_index]);
var buf_index: usize = paths[first_path_index].len;
var prev_path = paths[first_path_index];
assert(prev_path.len > 0);
var i: usize = first_path_index + 1;
while (i < paths.len) : (i += 1) {
const prev_path = paths[i - 1];
const this_path = paths[i];
const prev_sep = (prev_path.len != 0 and sepPredicate(prev_path[prev_path.len - 1]));
const this_sep = (this_path.len != 0 and sepPredicate(this_path[0]));
if (this_path.len == 0) continue;
const prev_sep = sepPredicate(prev_path[prev_path.len - 1]);
const this_sep = sepPredicate(this_path[0]);
if (!prev_sep and !this_sep) {
buf[buf_index] = separator;
buf_index += 1;
@ -76,6 +93,7 @@ fn joinSepMaybeZ(allocator: *Allocator, separator: u8, sepPredicate: fn (u8) boo
const adjusted_path = if (prev_sep and this_sep) this_path[1..] else this_path;
mem.copy(u8, buf[buf_index..], adjusted_path);
buf_index += adjusted_path.len;
prev_path = this_path;
}
if (zero) buf[buf.len - 1] = 0;
@ -148,6 +166,10 @@ test "join" {
try testJoinMaybeZWindows(&[_][]const u8{ "c:\\", "a", "b/", "c" }, "c:\\a\\b/c", zero);
try testJoinMaybeZWindows(&[_][]const u8{ "c:\\a/", "b\\", "/c" }, "c:\\a/b\\c", zero);
try testJoinMaybeZWindows(&[_][]const u8{ "", "c:\\", "", "", "a", "b\\", "c", "" }, "c:\\a\\b\\c", zero);
try testJoinMaybeZWindows(&[_][]const u8{ "c:\\a/", "", "b\\", "", "/c" }, "c:\\a/b\\c", zero);
try testJoinMaybeZWindows(&[_][]const u8{ "", "" }, "", zero);
try testJoinMaybeZPosix(&[_][]const u8{}, "", zero);
try testJoinMaybeZPosix(&[_][]const u8{ "/a/b", "c" }, "/a/b/c", zero);
try testJoinMaybeZPosix(&[_][]const u8{ "/a/b/", "c" }, "/a/b/c", zero);
@ -163,6 +185,10 @@ test "join" {
try testJoinMaybeZPosix(&[_][]const u8{ "a", "/c" }, "a/c", zero);
try testJoinMaybeZPosix(&[_][]const u8{ "a/", "/c" }, "a/c", zero);
try testJoinMaybeZPosix(&[_][]const u8{ "", "/", "a", "", "b/", "c", "" }, "/a/b/c", zero);
try testJoinMaybeZPosix(&[_][]const u8{ "/a/", "", "", "b/", "c" }, "/a/b/c", zero);
try testJoinMaybeZPosix(&[_][]const u8{ "", "" }, "", zero);
}
}