more robust treatment of suppressed quotes concerning replacement text -- for improved copy/paste behaviour;

--- a/doc-src/isabelle.sty	Mon Nov 08 00:00:47 2010 +0100
+++ b/doc-src/isabelle.sty	Mon Nov 08 11:28:22 2010 +0100
@@ -96,6 +96,7 @@
 }
 
 \newcommand{\isaliteral}[2]{#2}
+\newcommand{\isanil}{}
 
 
 % keyword and section markup
@@ -148,9 +149,9 @@
 \renewcommand{\isastylescript}{\footnotesize\it}%
 \renewcommand{\isacharunderscorekeyword}{\mbox{-}}%
 \renewcommand{\isacharbang}{\isamath{!}}%
-\renewcommand{\isachardoublequote}{}%
-\renewcommand{\isachardoublequoteopen}{}%
-\renewcommand{\isachardoublequoteclose}{}%
+\renewcommand{\isachardoublequote}{\isanil}%
+\renewcommand{\isachardoublequoteopen}{\isanil}%
+\renewcommand{\isachardoublequoteclose}{\isanil}%
 \renewcommand{\isacharhash}{\isamath{\#}}%
 \renewcommand{\isachardollar}{\isamath{\$}}%
 \renewcommand{\isacharpercent}{\isamath{\%}}%

--- a/doc-src/pdfsetup.sty	Mon Nov 08 00:00:47 2010 +0100
+++ b/doc-src/pdfsetup.sty	Mon Nov 08 11:28:22 2010 +0100
@@ -13,11 +13,11 @@
 \gdef\bold#1{\textbf{\hyperpage{#1}}}
 
 \urlstyle{rm}
-
 \ifpdf\relax\else\renewcommand{\url}[1]{\nolinkurl{#1}}\fi
 
 \ifpdf
 \ifnum\pdfminorversion<5\pdfminorversion=5\fi
 \renewcommand{\isaliteral}[2]{%
 \pdfliteral direct{/Span <</ActualText<#1>>> BDC}#2\pdfliteral direct{EMC}}
+\renewcommand{\isanil}{{\color{white}.}}
 \fi

--- a/lib/texinputs/isabelle.sty	Mon Nov 08 00:00:47 2010 +0100
+++ b/lib/texinputs/isabelle.sty	Mon Nov 08 11:28:22 2010 +0100
@@ -96,6 +96,7 @@
 }
 
 \newcommand{\isaliteral}[2]{#2}
+\newcommand{\isanil}{}
 
 
 % keyword and section markup
@@ -148,9 +149,9 @@
 \renewcommand{\isastylescript}{\footnotesize\it}%
 \renewcommand{\isacharunderscorekeyword}{\mbox{-}}%
 \renewcommand{\isacharbang}{\isamath{!}}%
-\renewcommand{\isachardoublequote}{}%
-\renewcommand{\isachardoublequoteopen}{}%
-\renewcommand{\isachardoublequoteclose}{}%
+\renewcommand{\isachardoublequote}{\isanil}%
+\renewcommand{\isachardoublequoteopen}{\isanil}%
+\renewcommand{\isachardoublequoteclose}{\isanil}%
 \renewcommand{\isacharhash}{\isamath{\#}}%
 \renewcommand{\isachardollar}{\isamath{\$}}%
 \renewcommand{\isacharpercent}{\isamath{\%}}%