[LyX/2.3.x] Fix display of gather in lefteqn mode

[Jean-Marc Lasgouttes]

commit e8d96cb9b159c0e61c669b9a64e5deff00b4be9b
Author: Jean-Marc Lasgouttes <lasgout...@lyx.org>
Date:   Thu Oct 4 16:05:46 2018 +0200

    Fix display of gather in lefteqn mode
    
    The column is flushed when the display of equations is flushed.
    
    Not sure what to do with RtL languages.
    
    Fixes bug 11324.
    
    (cherry picked from commit 7cb0284a3ffa469c4c99184725f5a3e0b4056508)
---
 src/mathed/InsetMathGrid.cpp  |    8 ++++++--
 src/mathed/InsetMathGrid.h    |    7 +++++--
 src/mathed/InsetMathHull.cpp  |    4 ++--
 src/mathed/InsetMathSplit.cpp |    5 +++--
 status.23x                    |    3 +++
 5 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/src/mathed/InsetMathGrid.cpp b/src/mathed/InsetMathGrid.cpp
index f015285..f962542 100644
--- a/src/mathed/InsetMathGrid.cpp
+++ b/src/mathed/InsetMathGrid.cpp
@@ -1843,15 +1843,19 @@ bool InsetMathGrid::getStatus(Cursor & cur, FuncRequest 
const & cmd,
 
 
 // static
-char InsetMathGrid::colAlign(HullType type, col_type col)
+char InsetMathGrid::colAlign(HullType type, col_type col, BufferParams const & 
bp)
 {
        switch (type) {
        case hullEqnArray:
                return "rcl"[col % 3];
 
        case hullMultline:
-       case hullGather:
                return 'c';
+       case hullGather:
+               if (!bp.is_math_indent)
+                       return 'c';
+               else
+                       return 'l';
 
        case hullAlign:
        case hullAlignAt:
diff --git a/src/mathed/InsetMathGrid.h b/src/mathed/InsetMathGrid.h
index 9cd22ea..2e48453 100644
--- a/src/mathed/InsetMathGrid.h
+++ b/src/mathed/InsetMathGrid.h
@@ -18,6 +18,8 @@
 
 namespace lyx {
 
+class BufferParams;
+
 
 /** Gridded math inset base class.
  *  This is the base to all grid-like editable math objects
@@ -267,8 +269,9 @@ protected:
 
        // The following two functions are used in InsetMathHull and
        // InsetMathSplit.
-       /// The value of a fixed col align for a certain hull type
-       static char colAlign(HullType type, col_type col);
+       /// The value of a fixed col align for a certain hull type (can
+       /// depend on the "indent math" setting).
+       static char colAlign(HullType type, col_type col,  BufferParams const 
&);
        /// The value of a fixed col spacing for a certain hull type
        static int colSpace(HullType type, col_type col);
 
diff --git a/src/mathed/InsetMathHull.cpp b/src/mathed/InsetMathHull.cpp
index 0f7e9a8..2c2cd41 100644
--- a/src/mathed/InsetMathHull.cpp
+++ b/src/mathed/InsetMathHull.cpp
@@ -446,7 +446,7 @@ bool InsetMathHull::idxLast(Cursor & cur) const
 // alignment is not implemented in the LyXHTML output.
 char InsetMathHull::defaultColAlign(col_type col)
 {
-       return colAlign(type_, col);
+       return colAlign(type_, col, buffer().params());
 }
 
 
@@ -468,7 +468,7 @@ char InsetMathHull::displayColAlign(idx_type idx) const
        case hullXAlignAt:
        case hullXXAlignAt:
        case hullFlAlign:
-               return colAlign(type_, col(idx));
+               return colAlign(type_, col(idx), buffer().params());
        default:
                break;
        }
diff --git a/src/mathed/InsetMathSplit.cpp b/src/mathed/InsetMathSplit.cpp
index c260e2e..200a0bc 100644
--- a/src/mathed/InsetMathSplit.cpp
+++ b/src/mathed/InsetMathSplit.cpp
@@ -16,6 +16,7 @@
 #include "MathStream.h"
 #include "MathSupport.h"
 
+#include "Buffer.h"
 #include "FuncRequest.h"
 #include "FuncStatus.h"
 #include "support/gettext.h"
@@ -61,7 +62,7 @@ char InsetMathSplit::defaultColAlign(col_type col)
            || name_ == "aligned"
            || name_ == "align"
            || name_ == "alignedat")
-               return colAlign(hullAlign, col);
+               return colAlign(hullAlign, col, buffer().params());
        return 'l';
 }
 
@@ -78,7 +79,7 @@ char InsetMathSplit::displayColAlign(idx_type idx) const
            || name_ == "aligned"
            || name_ == "align"
            || name_ == "alignedat")
-               return colAlign(hullAlign, col(idx));
+               return colAlign(hullAlign, col(idx), buffer().params());
        return InsetMathGrid::displayColAlign(idx);
 }
 
diff --git a/status.23x b/status.23x
index 1bc9f27..83beca4 100644
--- a/status.23x
+++ b/status.23x
@@ -128,6 +128,9 @@ What's new
 
 - Repair (de)activation of plural, capitalize, etc, for refstyle.
 
+- Fix display of gather environment in leqno mode (bug 11324).
+
+
 
 * INTERNALS