Remove Windows verbatim drive in path

`canonicalize` replaces the drive in a path with verbatim syntax,
e.g. `C:\Windows` turns into `\\?\C:\Windows`.

While Win32 apis handle verbatim paths nicely, commonly used Windows
shells like PowerShell and cmd do not, so we remove the prefix
before adding any paths to the database.

src/db.rs

@@ -1,5 +1,6 @@
 use crate::config;
 use crate::dir::{Dir, Epoch, Rank};
+use crate::util;
 
 use anyhow::{anyhow, bail, Context, Result};
 use serde::{Deserialize, Serialize};
@@ -188,6 +189,7 @@ impl DB {
         let path_abs = path
             .as_ref()
             .canonicalize()
+            .and_then(|path| Ok(util::remove_verbatim_disk_in_path(path)))
             .with_context(|| anyhow!("could not access directory: {}", path.as_ref().display()))?;
 
         match self.data.dirs.iter_mut().find(|dir| dir.path == path_abs) {

src/util.rs

@@ -7,7 +7,7 @@ use anyhow::{anyhow, bail, Context, Result};
 
 use std::cmp::Reverse;
 use std::io::{Read, Write};
-use std::path::Path;
+use std::path::{Component, Path, PathBuf, Prefix};
 use std::process::{Command, Stdio};
 use std::time::SystemTime;
 
@@ -26,6 +26,28 @@ pub fn path_to_bytes<P: AsRef<Path>>(path: &P) -> Result<&[u8]> {
     }
 }
 
+#[cfg(not(windows))]
+pub fn remove_verbatim_disk_in_path(path: PathBuf) -> PathBuf {
+    path
+}
+
+#[cfg(windows)]
+pub fn remove_verbatim_disk_in_path(path: PathBuf) -> PathBuf {
+    let mut new_path = PathBuf::new();
+    for component in path.components() {
+        if let Component::Prefix(prefix) = component {
+            if let Prefix::VerbatimDisk(drive) = prefix.kind() {
+                new_path.push(format!("{}:", drive as char));
+                continue;
+            }
+        }
+
+        new_path.push(component);
+    }
+
+    new_path
+}
+
 #[cfg(unix)]
 pub fn bytes_to_path(bytes: &[u8]) -> Result<&Path> {
     use std::ffi::OsStr;