Update bash_completion.py

Author: anki-code

bash_completion.py

@@ -288,6 +288,7 @@ def bash_completions(
     paths=None,
     command=None,
     quote_paths=_bash_quote_paths,
+    arg_index=None,
     **kwargs
 ):
     """Completes based on results from BASH completion.
@@ -320,7 +321,9 @@ def bash_completions(
         this as the default is acceptable 99+% of the time. This function should
         return a set of the new paths and a boolean for whether the paths were
         quoted.
-
+    arg_index : int, optional
+        The current prefix's index in the args.
+        
     Returns
     -------
     rtn : set of str
@@ -336,24 +339,27 @@ def bash_completions(
     splt = line.split()
     cmd = splt[0]
     cmd = os.path.basename(cmd)
-    idx = n = 0
     prev = ""
-    for n, tok in enumerate(splt):
-        if tok == prefix:
-            idx = line.find(prefix, idx)
-            if idx >= begidx:
-                break
-        prev = tok
-
-    if len(prefix) == 0:
-        prefix_quoted = '""'
-        n += 1
+    if arg_index is not None:
+        n = arg_index
+        if arg_index > 0:
+            prev = splt[arg_index - 1]
     else:
-        prefix_quoted = shlex.quote(prefix)
+        # find `n` and `prev` by ourselves
+        idx = n = 0
+        for n, tok in enumerate(splt):  # noqa
+            if tok == prefix:
+                idx = line.find(prefix, idx)
+                if idx >= begidx:
+                    break
+            prev = tok
+        if len(prefix) == 0:
+            n += 1
+    prefix_quoted = shlex.quote(prefix)
 
     script = BASH_COMPLETE_SCRIPT.format(
         source=source,
-        line=" ".join(shlex.quote(p) for p in splt),
+        line=" ".join(shlex.quote(p) for p in splt if p),
         comp_line=shlex.quote(line),
         n=n,
         cmd=shlex.quote(cmd),