Invert transform before assigning intersection #889

This will always return the intersection in the untransformed scope, so
it is necessary to apply the same transformation as was active when
`\pgfintersectionofpaths' was called, although that should be the case
most of the time.

tex/generic/pgf/frontendlayer/tikz/libraries/tikzlibraryintersections.code.tex

@@ -104,7 +104,7 @@
         \pgfmathloop%
         \ifnum\pgfmathcounter>\pgfintersectionsolutions\relax%
         \else%
-          \path[reset cm]\pgfextra{\pgftransformshift{\pgfpointintersectionsolution{\pgfmathcounter}}}%
+          \path\pgfextra{\pgftransformshift{\pgfpointintersectionsolution{\pgfmathcounter}}}%
             coordinate (\tikz@intersect@@name-\pgfmathcounter);
         \repeatpgfmathloop%
         \ifx\tikz@intersect@by\pgfutil@empty%

tex/generic/pgf/libraries/pgflibraryintersections.code.tex

@@ -352,7 +352,9 @@
     \pgf@iflinesintersect{#1}{#2}{#3}{#4}%
     {%
         \pgfextract@process\pgf@intersect@solution@candidate{%
+            \pgftransforminvert
             % pgf@x and pgf@y are already assigned by \pgf@iflinesintersect
+            \pgfpointtransformed{\pgfqpoint{\pgf@x}{\pgf@y}}%
         }%
         \pgf@ifsolution@duplicate{\pgf@intersect@solution@candidate}{%
             % ah - we a duplicate. Apparently, we have a hit on an