Regexp replace \N freeze

[ProgerXP]

Any document, do Replace from \N to 123 - the program will become unresponsive.

[cshnik]

Fixed.

[ProgerXP]

What was the cause? What's special about \N?

[cshnik]

What was the cause? What's special about \N?

There was an unhandled exception thrown from regexp internals when trying to compile/use incorrectly formatted value. \N is not a valid special character.

[ProgerXP]

Was it necessary to change Scintilla internals? Notepad++ doesn't have such a problem.

[cshnik]

Was it necessary to change Scintilla internals?

BoostRegExSearch.cxx is not a part of original Scintilla's code base. This is an auxiliary class for Scintilla which implements custom regex capabilities. We use adopted boost regex implementation which originally came from Notepad++. Since boost regex is written in C++ our code should rely on exception model which is used to notify about incorrect values.

[ProgerXP]

boost::regex_constants::ECMAScript

What does this flag do?

---

+		try
+		{
+			found = boost::regex_search(itStart, itEnd, _match, _regex, search._boostRegexFlags);
+		}
+		catch (...)
+		{
+			found = false;
+		} 

Cannot you catch the exception in our code rather than silencing it in BoostRegExSearch?

[cshnik]

boost::regex_constants::ECMAScript

What does this flag do?

https://www.boost.org/doc/libs/1_33_1/libs/regex/doc/syntax_option_type.html:

Element	Standardized	Effect when set
ECMAScript	Yes	Specifies that the grammar recognized by the regular expression engine uses its normal semantics: that is the same as that given in the ECMA-262, ECMAScript Language Specification, Chapter 15 part 10, RegExp (Regular Expression) Objects (FWD.1).boost.regex also recognizes all of the perl-compatible (?...) extensions in this mode.

Cannot you catch the exception in our code rather than silencing it in BoostRegExSearch?

No. Actually, BoostRegExSearch is our module which implements direct regex-calls(). This module is written in C++ to embed custom regex engine into Scintilla (implemented class is inherited from RegexSearchBase). Processing of any exceptions raised from boost regex engine is a responsibility of this class.