CORE-2929 - 'Invalid ESCAPE sequence' when connecting to the database

doc/README.connection_string_charset.txt

@@ -31,16 +31,6 @@ may automatically convert the filename and insert the DPB. Clients older than v2
 so the received filenames are going to be considered as on the server codepage. We again guarantee
 backward compatibility when client and server codepage are the same.
 
-The OS codepage and UTF-8 may not be the better choice for filenames. For example, if you had a
-ISQL (or some other tool) script and that script uses another connection charset. You could not
-correctly edit a script (or any file) using multiple character sets (codepages). So you may now
-encode any Unicode character as ASCII characters on the connection string filename. That's
-accomplished using the symbol #. It is a prefix for an Unicode code point number (in hexadecimal
-format, like U+XXXX notation). You should write it in this way: #XXXX with X being 0-9, a-f, A-F.
-If you want to use the literal #, you could use ## or #0023 (the code point number for it).
-That character is interpreted with this new semantics at the server even if the client is older
-than v2.5.
-
 The OS codepage used for conversions is:
 - Windows: The Windows ANSI code page
 - Others: UTF-8

src/jrd/isc_file.cpp

@@ -1696,12 +1696,14 @@ void ISC_utf8ToSystem(Firebird::AbstractString& str)
 // Escape Unicode characters from a string
 void ISC_escape(AbstractString& str)
 {
+#if 0	// CORE-2929
 	size_t pos = 0;
 	while ((pos = str.find_first_of("#", pos)) != npos)
 	{
 		str.insert(pos, "#");
 		pos += 2;
 	}
+#endif
 }
 
 
@@ -1736,6 +1738,7 @@ static inline void FB_U8_APPEND_UNSAFE(char* s, int& i, const int c)
 // Unescape Unicode characters from a string
 void ISC_unescape(AbstractString& str)
 {
+#if 0	// CORE-2929
 	size_t pos = 0;
 	while ((pos = str.find_first_of("#", pos)) != npos)
 	{
@@ -1764,4 +1767,5 @@ void ISC_unescape(AbstractString& str)
 		else
 			status_exception::raise(Arg::Gds(isc_bad_conn_str) << Arg::Gds(isc_escape_invalid));
 	}
+#endif
 }