Merge bitcoin/bitcoin#27302: init: Error if ignored bitcoin.conf file is found

eefe56967b bugfix: Fix incorrect debug.log config file path (Ryan Ofsky)
3746f00be1 init: Error if ignored bitcoin.conf file is found (Ryan Ofsky)
398c3719b0 lint: Fix lint-format-strings false positives when format specifiers have argument positions (Ryan Ofsky)

Pull request description:

  Show an error on startup if a bitcoin datadir that is being used contains a `bitcoin.conf` file that is ignored. There are two cases where this could happen:

  - One case reported in [#27246 (comment)](https://github.com/bitcoin/bitcoin/issues/27246#issuecomment-1470006043) happens when a `bitcoin.conf` file in the default datadir (e.g. `$HOME/.bitcoin/bitcoin.conf`) has a `datadir=/path` line that sets different datadir containing a second `bitcoin.conf` file. Currently the second `bitcoin.conf` file is ignored with no warning.

  - Another way this could happen is if a `-conf=` command line argument points to a configuration file with a `datadir=/path` line and that path contains a `bitcoin.conf` file, which is currently ignored.

  This change only adds an error message and doesn't change anything about way settings are applied. It also doesn't trigger errors if there are redundant `-datadir` or `-conf` settings pointing at the same configuration file, only if they are pointing at different files and one file is being ignored.

ACKs for top commit:
  pinheadmz:
    re-ACK eefe56967b
  willcl-ark:
    re-ACK eefe56967b
  TheCharlatan:
    ACK eefe56967b

Tree-SHA512: 939a98a4b271b5263d64a2df3054c56fcde94784edf6f010d78693a371c38aa03138ae9cebb026b6164bbd898d8fd0845a61a454fd996e328fd7bcf51c580c2b

test/lint/run-lint-format-strings.py

@@ -241,20 +241,32 @@ def count_format_specifiers(format_string):
     3
     >>> count_format_specifiers("foo %d bar %i foo %% foo %*d foo")
     4
+    >>> count_format_specifiers("foo %5$d")
+    5
+    >>> count_format_specifiers("foo %5$*7$d")
+    7
     """
     assert type(format_string) is str
     format_string = format_string.replace('%%', 'X')
-    n = 0
-    in_specifier = False
-    for i, char in enumerate(format_string):
-        if char == "%":
-            in_specifier = True
+    n = max_pos = 0
+    for m in re.finditer("%(.*?)[aAcdeEfFgGinopsuxX]", format_string, re.DOTALL):
+        # Increase the max position if the argument has a position number like
+        # "5$", otherwise increment the argument count.
+        pos_num, = re.match(r"(?:(^\d+)\$)?", m.group(1)).groups()
+        if pos_num is not None:
+            max_pos = max(max_pos, int(pos_num))
+        else:
             n += 1
-        elif char in "aAcdeEfFgGinopsuxX":
-            in_specifier = False
-        elif in_specifier and char == "*":
+
+        # Increase the max position if there is a "*" width argument with a
+        # position like "*7$", and increment the argument count if there is a
+        # "*" width argument with no position.
+        star, star_pos_num = re.match(r"(?:.*?(\*(?:(\d+)\$)?)|)", m.group(1)).groups()
+        if star_pos_num is not None:
+            max_pos = max(max_pos, int(star_pos_num))
+        elif star is not None:
             n += 1
-    return n
+    return max(n, max_pos)
 
 
 def main():