Implement PCRE2_EXTRA_ESCAPED_CR_IS_LF

git-svn-id: svn://vcs.exim.org/pcre2/code/trunk@1017 6239d852-aaf2-0410-a92c-79f79f948069

1 files changed, 8 insertions, 2 deletions

diff --git a/doc/html/pcre2pattern.html b/doc/html/pcre2pattern.html
index e43e98e..8a2ef4e 100644
--- a/doc/html/pcre2pattern.html
+++ b/doc/html/pcre2pattern.html
@@ -393,7 +393,7 @@ these escapes are as follows:
   \e          escape (hex 1B)
   \f          form feed (hex 0C)
   \n          linefeed (hex 0A)
-  \r          carriage return (hex 0D)
+  \r          carriage return (hex 0D) (but see below)
   \t          tab (hex 09)
   \0dd        character with octal code 0dd
   \ddd        character with octal code ddd, or backreference
@@ -403,6 +403,12 @@ these escapes are as follows:
   \N{U+hhh..} character with Unicode hex code point hhh..
   \uhhhh      character with hex code hhhh (when PCRE2_ALT_BSUX is set)
 </pre>
+There are some legacy applications where the escape sequence \r is expected to
+match a newline. If the PCRE2_EXTRA_ESCAPED_CR_IS_LF option is set, \r in a
+pattern is converted to \n so that it matches a LF (linefeed) instead of a CR
+(carriage return) character.
+</P>
+<P>
 The \N{U+hhh..} escape sequence is recognized only when the PCRE2_UTF option
 is set, that is, when PCRE2 is operating in a Unicode mode. Perl also uses
 \N{name} to specify characters by Unicode name; PCRE2 does not support this.
@@ -3624,7 +3630,7 @@ Cambridge, England.
 </P>
 <br><a name="SEC30" href="#TOC1">REVISION</a><br>
 <P>
-Last updated: 04 September 2018
+Last updated: 21 September 2018
 <br>
 Copyright &copy; 1997-2018 University of Cambridge.
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