From cebc9b0ae2b12c61eac39a3c599edb3b1b65dd54 Mon Sep 17 00:00:00 2001
From: Damien George <damien@micropython.org>
Date: Thu, 20 Jun 2024 12:11:26 +1000
Subject: [PATCH] tools/mpremote: Fix absolute path usage in remote mounted
 VFS.

Prior to this fix the current working path in the remote VFS would always
be prepended to the requested path to get the full path, even if the
requested path was already absolute, ie starting with "/".

So `os.chdir("/remote/dir1")` would set the working path to "/dir1/", and
a subsequent call with an absolute path like `os.listdir("/remote/dir2")`
would try to list the directory "/dir1/dir2/".

Fixes issue #15308.

Signed-off-by: Damien George <damien@micropython.org>
---
 tools/mpremote/mpremote/transport_serial.py | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/tools/mpremote/mpremote/transport_serial.py b/tools/mpremote/mpremote/transport_serial.py
index 3b4cd0007..a97b7e0a0 100644
--- a/tools/mpremote/mpremote/transport_serial.py
+++ b/tools/mpremote/mpremote/transport_serial.py
@@ -838,6 +838,9 @@ class RemoteFS:
     def __init__(self, cmd):
         self.cmd = cmd
 
+    def _abspath(self, path):
+        return path if path.startswith("/") else self.path + path
+
     def mount(self, readonly, mkfs):
         pass
 
@@ -859,7 +862,7 @@ class RemoteFS:
     def remove(self, path):
         c = self.cmd
         c.begin(CMD_REMOVE)
-        c.wr_str(self.path + path)
+        c.wr_str(self._abspath(path))
         res = c.rd_s32()
         c.end()
         if res < 0:
@@ -868,8 +871,8 @@ class RemoteFS:
     def rename(self, old, new):
         c = self.cmd
         c.begin(CMD_RENAME)
-        c.wr_str(self.path + old)
-        c.wr_str(self.path + new)
+        c.wr_str(self._abspath(old))
+        c.wr_str(self._abspath(new))
         res = c.rd_s32()
         c.end()
         if res < 0:
@@ -878,7 +881,7 @@ class RemoteFS:
     def mkdir(self, path):
         c = self.cmd
         c.begin(CMD_MKDIR)
-        c.wr_str(self.path + path)
+        c.wr_str(self._abspath(path))
         res = c.rd_s32()
         c.end()
         if res < 0:
@@ -887,7 +890,7 @@ class RemoteFS:
     def rmdir(self, path):
         c = self.cmd
         c.begin(CMD_RMDIR)
-        c.wr_str(self.path + path)
+        c.wr_str(self._abspath(path))
         res = c.rd_s32()
         c.end()
         if res < 0:
@@ -896,7 +899,7 @@ class RemoteFS:
     def stat(self, path):
         c = self.cmd
         c.begin(CMD_STAT)
-        c.wr_str(self.path + path)
+        c.wr_str(self._abspath(path))
         res = c.rd_s8()
         if res < 0:
             c.end()
@@ -912,7 +915,7 @@ class RemoteFS:
     def ilistdir(self, path):
         c = self.cmd
         c.begin(CMD_ILISTDIR_START)
-        c.wr_str(self.path + path)
+        c.wr_str(self._abspath(path))
         res = c.rd_s8()
         c.end()
         if res < 0:
@@ -933,7 +936,7 @@ class RemoteFS:
     def open(self, path, mode):
         c = self.cmd
         c.begin(CMD_OPEN)
-        c.wr_str(self.path + path)
+        c.wr_str(self._abspath(path))
         c.wr_str(mode)
         fd = c.rd_s8()
         c.end()