Fix tex2lyx include output for roundtrip

In roundtrip mode, tex2lyx produces documents with extension lyx.lyx, so that
the original files are not overwritten on re-export. This was not done for
included documents which were converted, and this broke 'make dist'.

src/tex2lyx/test/CJK.lyx.lyx

@@ -1,5 +1,5 @@
 #LyX file created by tex2lyx 2.1.0dev
-\lyxformat 471
+\lyxformat 472
 \begin_document
 \begin_header
 \textclass article

src/tex2lyx/test/CJKutf8.lyx.lyx

@@ -1,5 +1,5 @@
 #LyX file created by tex2lyx 2.1.0dev
-\lyxformat 471
+\lyxformat 472
 \begin_document
 \begin_header
 \textclass article

src/tex2lyx/test/XeTeX-polyglossia.lyx.lyx

@@ -1,5 +1,5 @@
 #LyX file created by tex2lyx 2.1.0dev
-\lyxformat 471
+\lyxformat 472
 \begin_document
 \begin_header
 \textclass article

src/tex2lyx/test/box-color-size-space-align.lyx.lyx

@@ -1,5 +1,5 @@
 #LyX file created by tex2lyx 2.1.0dev
-\lyxformat 471
+\lyxformat 472
 \begin_document
 \begin_header
 \textclass article
@@ -142,7 +142,7 @@ has_inner_box 1
 inner_pos "c"
 use_parbox 0
 use_makebox 1
-width "-999col%"
+width ""
 special "none"
 height "1in"
 height_special "totalheight"
@@ -663,7 +663,7 @@ has_inner_box 0
 inner_pos "c"
 use_parbox 0
 use_makebox 0
-width "-999col%"
+width ""
 special "none"
 height "1in"
 height_special "totalheight"
@@ -688,7 +688,7 @@ has_inner_box 0
 inner_pos "c"
 use_parbox 0
 use_makebox 0
-width "-999col%"
+width ""
 special "none"
 height "1in"
 height_special "totalheight"

src/tex2lyx/test/test-insets.lyx.lyx

@@ -1,5 +1,5 @@
 #LyX file created by tex2lyx 2.1.0dev
-\lyxformat 471
+\lyxformat 472
 \begin_document
 \begin_header
 \textclass article
@@ -734,7 +734,7 @@ We can input files too, like this
 \begin_inset CommandInset include
 LatexCommand input
 preview false
-filename "DummyDocument.lyx"
+filename "DummyDocument.lyx.lyx"
 
 \end_inset
 
@@ -742,7 +742,7 @@ filename "DummyDocument.lyx"
 \begin_inset CommandInset include
 LatexCommand include
 preview false
-filename "Dummy Document.lyx"
+filename "Dummy Document.lyx.lyx"
 
 \end_inset
 
@@ -750,7 +750,7 @@ filename "Dummy Document.lyx"
 \begin_inset CommandInset include
 LatexCommand include
 preview false
-filename "Dummy Document.lyx"
+filename "Dummy Document.lyx.lyx"
 
 \end_inset
 
@@ -758,7 +758,7 @@ filename "Dummy Document.lyx"
 \begin_inset CommandInset include
 LatexCommand include
 preview false
-filename "Dummy~Document.lyx"
+filename "Dummy~Document.lyx.lyx"
 
 \end_inset
 
@@ -766,7 +766,7 @@ filename "Dummy~Document.lyx"
 \begin_inset CommandInset include
 LatexCommand include
 preview false
-filename "Dummy~Document.lyx"
+filename "Dummy~Document.lyx.lyx"
 
 \end_inset
 

src/tex2lyx/test/test-modules.lyx.lyx

@@ -1,5 +1,5 @@
 #LyX file created by tex2lyx 2.1.0dev
-\lyxformat 471
+\lyxformat 472
 \begin_document
 \begin_header
 \textclass amsart

src/tex2lyx/test/test-refstyle-theorems.lyx.lyx

@@ -1,5 +1,5 @@
 #LyX file created by tex2lyx 2.1.0dev
-\lyxformat 471
+\lyxformat 472
 \begin_document
 \begin_header
 \textclass book

src/tex2lyx/test/test-structure.lyx.lyx

@@ -1,5 +1,5 @@
 #LyX file created by tex2lyx 2.1.0dev
-\lyxformat 471
+\lyxformat 472
 \begin_document
 \begin_header
 \textclass article

src/tex2lyx/test/test.lyx.lyx

@@ -1,5 +1,5 @@
 #LyX file created by tex2lyx 2.1.0dev
-\lyxformat 471
+\lyxformat 472
 \begin_document
 \begin_header
 \textclass article

src/tex2lyx/test/verbatim.lyx.lyx

@@ -1,5 +1,5 @@
 #LyX file created by tex2lyx 2.1.0dev
-\lyxformat 471
+\lyxformat 472
 \begin_document
 \begin_header
 \textclass article

src/tex2lyx/tex2lyx.cpp

@@ -818,6 +818,12 @@ bool skipChildren()
 }
 
 
+bool roundtripMode()
+{
+	return roundtrip;
+}
+
+
 namespace {
 
 /*!

src/tex2lyx/tex2lyx.h

@@ -193,6 +193,8 @@ extern bool overwriteFiles();
 extern bool copyFiles();
 /// Shall we skip child documents and keep them as TeX?
 extern bool skipChildren();
+/// Does tex2lyx run in roundtrip mode?
+extern bool roundtripMode();
 
 
 /*!

src/tex2lyx/text.cpp

@@ -3929,8 +3929,8 @@ void parse_text(Parser & p, ostream & os, unsigned flags, bool outer,
 				string const absfigname =
 					changeExtension(abstexname, ".fig");
 				fix_child_filename(filename);
-				string const lyxname =
-					changeExtension(filename, ".lyx");
+				string const lyxname = changeExtension(filename,
+					roundtripMode() ? ".lyx.lyx" : ".lyx");
 				string const abslyxname = makeAbsPath(
 					lyxname, getParentFilePath(false)).absFileName();
 				bool xfig = false;