Merge pull request #490 from impact27/canonic_inode

PR: Use inodes for single canonic file path (Debugger)

spyder_kernels/console/tests/test_console_kernel.py

@@ -1391,5 +1391,26 @@ def test_django_settings(kernel):
     assert "'settings':" in nsview
 
 
+def test_hard_link_pdb(tmpdir):
+    """
+    Test that breakpoints on a file are recognised even when the path is 
+    different.
+    """
+    # Create a file and a hard link
+    d = tmpdir.join("file.py")
+    d.write('def func():\n    bb = "hello"\n')
+    folder = tmpdir.join("folder")
+    os.mkdir(folder)
+    hard_link = folder.join("file.py")
+    os.link(d, hard_link)
+
+    # Make sure both paths point to the same file
+    assert os.path.samefile(d, hard_link)
+
+    # Make sure canonic returns the same path for a single file
+    pdb_obj = SpyderPdb()
+    assert pdb_obj.canonic(str(d)) == pdb_obj.canonic(str(hard_link))
+
+
 if __name__ == "__main__":
     pytest.main()

spyder_kernels/customize/spyderpdb.py

@@ -118,6 +118,10 @@ def __init__(self, completekey='tab', stdin=None, stdout=None,
         # Fixes spyder-ide/spyder#20639.
         self._predicates["debuggerskip"] = False
 
+        # Save seen files inodes
+        self._canonic_inode_to_filename = {}
+        self._canonic_filename_to_inode = {}
+
     # --- Methods overriden for code execution
     def print_exclamation_warning(self):
         """Print pdb warning for exclamation mark."""
@@ -621,8 +625,42 @@ def _cmdloop(self):
 
     @lru_cache
     def canonic(self, filename):
-        """Return canonical form of filename."""
-        return super().canonic(filename)
+        """
+        Return canonical form of filename.
+
+        In some case two path can point to the same file. For this reason
+        os.path.samefile uses os.stat. Here we normalise the path with os.stat
+        so a single path is returned for the same file.
+
+        see: https://docs.python.org/3/library/os.path.html#os.path.samefile
+        note: os.stat can be slow on windows so call it once per file.
+        """
+        if filename == "<" + filename[1:-1] + ">":
+            return filename
+
+        filename = super().canonic(filename)
+
+        if filename in self._canonic_filename_to_inode:
+            inode = self._canonic_filename_to_inode[filename]
+        else:
+            try:
+                stat = os.stat(filename)
+            except OSError:
+                self._canonic_filename_to_inode[filename] = None
+                return filename
+
+            inode = (stat.st_dev, stat.st_ino)
+            if stat.st_ino == 0:
+                inode = None
+            self._canonic_filename_to_inode[filename] = inode
+            if inode is not None and inode not in self._canonic_inode_to_filename:
+                # First time this inode is seen
+                self._canonic_inode_to_filename[inode] = filename
+
+        if inode is None:
+            return filename
+        return self._canonic_inode_to_filename[inode]
+
 
     def do_exitdb(self, arg):
         """Exit the debugger"""