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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - temp_directory_path() returns path with trailing slash"
href="https://bugs.llvm.org/show_bug.cgi?id=45307">45307</a>
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<th>Summary</th>
<td>temp_directory_path() returns path with trailing slash
</td>
</tr>
<tr>
<th>Product</th>
<td>libc++
</td>
</tr>
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<th>Version</th>
<td>unspecified
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>All Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>ldionne@apple.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org, mclow.lists@gmail.com
</td>
</tr></table>
<p>
<div>
<pre>The following program works when run in an empty environment, but not when
TEMPDIR or some other temporary-directory-pointing environment variable is
defined:
$ cat <<EOF | clang++ -xc++ -std=c++17 - && ./a.out
#include <filesystem>
#include <iostream>
namespace fs = std::filesystem;
int main() {
fs::path tmp = fs::temp_directory_path();
fs::path p = tmp / "hello";
std::cout << "tmp = " << tmp << std::endl;
std::cout << "p.parent_path() = " << p.parent_path() << std::endl;
assert(p.parent_path() == tmp);
}
EOF
When run as `./a.out`, the program fails:
tmp = "/var/folders/10/r6bw68bs5b9gwjtrnl9dz0vm0000gn/T/"
p.parent_path() = "/var/folders/10/r6bw68bs5b9gwjtrnl9dz0vm0000gn/T"
Assertion failed: (p.parent_path() == tmp), function main, file <stdin>,
line 9.
Unsurprisingly, the environment contains the following entry:
TMPDIR=/var/folders/10/r6bw68bs5b9gwjtrnl9dz0vm0000gn/T/
When run as `env -i ./a.out`, the program succeeds and prints the following:
tmp = "/tmp"
p.parent_path() = "/tmp"
Comparison of paths is based on comparing the file-names exposed by begin()
through end(), and that is specified to yield an empty element at the end if
the path ends with a directory separator. So the comparison appears to be
behaving correctly.
However, I believe temp_directory_path() should normalize its return value and
not return a path with a trailing slash if the path it picks up from the
environment has a trailing slash. The reason is that the Standard says
(<a href="http://eel.is/c++draft/fs.op.temp.dir.path#5">http://eel.is/c++draft/fs.op.temp.dir.path#5</a>):
Example: For POSIX-based operating systems, an implementation might return
the path supplied by the first environment variable found in the list TMPDIR,
TMP, TEMP, TEMPDIR, or if none of these are found, "/tmp".
It seems weird that we'd return a path with a trailing slash when found in an
environment variable, but just "/tmp" without a trailing slash otherwise.</pre>
</div>
</p>
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