From 8be0ec0db5731b2089462ac81abb67c108cd7840 Mon Sep 17 00:00:00 2001
From: Enrico Forestieri <forenr@lyx.org>
Date: Sun, 22 Oct 2017 13:12:33 +0200
Subject: [PATCH] Fix issue with change-tracked deleted display math

- If a display math not starting a new paragraph is deleted, the
  current \lyxdeleted macro (if any) must be closed and a new one
  started, otherwise the display math will be shifted up.

- Use \linewidth instead of \columnwidth because the former will adapt
  to the reduced horizontal width in list environments, avoiding shifting
  to the right the diplay math.

(cherry picked from commit 7f23ca912c5e92bf30bdc05b6d801082f6643e8e)
---
 src/Changes.cpp              | 13 ++++++++-----
 src/Paragraph.cpp            | 27 +++++++++++++++++++++++----
 src/mathed/InsetMathHull.cpp |  8 ++++----
 3 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/src/Changes.cpp b/src/Changes.cpp
index 8d4933c55f..b4226582f4 100644
--- a/src/Changes.cpp
+++ b/src/Changes.cpp
@@ -394,11 +394,16 @@ int Changes::latexMarkChange(otexstream & os, BufferParams const & bparams,
 
 	int column = 0;
 
+	bool const dvipost = LaTeXFeatures::isAvailable("dvipost") &&
+			(runparams.flavor == OutputParams::LATEX
+			 || runparams.flavor == OutputParams::DVILUATEX);
+
 	if (oldChange.type != Change::UNCHANGED) {
 		// close \lyxadded or \lyxdeleted
 		os << '}';
 		column++;
-		if (oldChange.type == Change::DELETED && !runparams.wasDisplayMath)
+		if (oldChange.type == Change::DELETED
+		    && !runparams.wasDisplayMath && !dvipost)
 			--runparams.inulemcmd;
 	}
 
@@ -410,7 +415,7 @@ int Changes::latexMarkChange(otexstream & os, BufferParams const & bparams,
 	docstring macro_beg;
 	if (change.type == Change::DELETED) {
 		macro_beg = from_ascii("\\lyxdeleted{");
-		if (!runparams.inDisplayMath)
+		if (!runparams.inDisplayMath && !dvipost)
 			++runparams.inulemcmd;
 	}
 	else if (change.type == Change::INSERTED)
@@ -422,9 +427,7 @@ int Changes::latexMarkChange(otexstream & os, BufferParams const & bparams,
 
 	// signature needed by \lyxsout to correctly strike out display math
 	if (change.type == Change::DELETED && runparams.inDisplayMath
-	    && (!LaTeXFeatures::isAvailable("dvipost")
-		|| (runparams.flavor != OutputParams::LATEX
-		    && runparams.flavor != OutputParams::DVILUATEX))) {
+	    && !dvipost) {
 		if (os.afterParbreak())
 			str += from_ascii("\\\\\\noindent\n");
 		else
diff --git a/src/Paragraph.cpp b/src/Paragraph.cpp
index c9a234d01f..859896900f 100644
--- a/src/Paragraph.cpp
+++ b/src/Paragraph.cpp
@@ -2454,6 +2454,8 @@ void Paragraph::latex(BufferParams const & bparams,
 		runparams.wasDisplayMath = runparams.inDisplayMath;
 		runparams.inDisplayMath = false;
 		bool deleted_display_math = false;
+		Change const & change = runparams.inDeletedInset
+			? runparams.changeOfDeletedInset : lookupChange(i);
 
 		// Check whether a display math inset follows
 		if (d->text_[i] == META_INSET
@@ -2468,11 +2470,28 @@ void Paragraph::latex(BufferParams const & bparams,
 				// cannot set it here because it is a counter.
 				deleted_display_math = isDeleted(i);
 			}
+			if (bparams.output_changes && deleted_display_math
+			    && runningChange == change
+			    && change.type == Change::DELETED
+			    && !os.afterParbreak()) {
+				// A display math in the same paragraph follows.
+				// We have to close and then reopen \lyxdeleted,
+				// otherwise the math will be shifted up.
+				OutputParams rp = runparams;
+				if (open_font) {
+					bool needPar = false;
+					column += running_font.latexWriteEndChanges(
+						os, bparams, rp, basefont,
+						basefont, needPar);
+					open_font = false;
+				}
+				basefont = getLayoutFont(bparams, outerfont);
+				running_font = basefont;
+				column += Changes::latexMarkChange(os, bparams,
+					Change(Change::INSERTED), change, rp);
+			}
 		}
 
-		Change const & change = runparams.inDeletedInset
-			? runparams.changeOfDeletedInset : lookupChange(i);
-
 		if (bparams.output_changes && runningChange != change) {
 			if (open_font) {
 				bool needPar = false;
@@ -2549,7 +2568,7 @@ void Paragraph::latex(BufferParams const & bparams,
 		char_type const c = d->text_[i];
 
 		// A display math inset inside an ulem command will be output
-		// as a box of width \columnwidth, so we have to either disable
+		// as a box of width \linewidth, so we have to either disable
 		// indentation if the inset starts a paragraph, or start a new
 		// line to accommodate such box. This has to be done before
 		// writing any font changing commands.
diff --git a/src/mathed/InsetMathHull.cpp b/src/mathed/InsetMathHull.cpp
index e07d5984b2..78175f3f70 100644
--- a/src/mathed/InsetMathHull.cpp
+++ b/src/mathed/InsetMathHull.cpp
@@ -126,14 +126,14 @@ namespace {
 		if (os.strikeoutMath()) {
 			if (os.ulemCmd() == WriteStream::UNDERLINE)
 				os << "\\raisebox{-\\belowdisplayshortskip}{"
-				      "\\lyxmathsout{\\parbox[b]{\\columnwidth}{";
+				      "\\lyxmathsout{\\parbox[b]{\\linewidth}{";
 			else
-				os << "\\lyxmathsout{\\parbox{\\columnwidth}{";
+				os << "\\lyxmathsout{\\parbox{\\linewidth}{";
 		} else if (os.ulemCmd() == WriteStream::UNDERLINE)
 			os << "\\raisebox{-\\belowdisplayshortskip}{"
-			      "\\parbox[b]{\\columnwidth}{";
+			      "\\parbox[b]{\\linewidth}{";
 		else if (os.ulemCmd() == WriteStream::STRIKEOUT)
-			os << "\\parbox{\\columnwidth}{";
+			os << "\\parbox{\\linewidth}{";
 	}
 
 
-- 
2.39.5