From 19579463fa303057c7a6004e9299bcf9a505c29b Mon Sep 17 00:00:00 2001
From: Yaraslau Tamashevich <yaraslau.tamashevich@gmail.com>
Date: Tue, 16 Jul 2024 09:14:29 +0300
Subject: [PATCH] Preserve spaces on resize

Signed-off-by: Christian Parpart <christian@parpart.family>
---
 metainfo.xml                |  1 +
 src/vtbackend/CellUtil.h    |  2 +-
 src/vtbackend/Grid_test.cpp | 19 +++++++++++++++++--
 src/vtbackend/Line.cpp      | 13 +++++--------
 4 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/metainfo.xml b/metainfo.xml
index 0bee96c0ef..ff5025e8c3 100644
--- a/metainfo.xml
+++ b/metainfo.xml
@@ -134,6 +134,7 @@
           <li>Do not export the `TERM` environment variable on Windows OS (when using ConPTY).</li>
           <li>Fixes resize of trivial line (#916)</li>
           <li>Fixes copying of wrapped line</li>
+          <li>Fixes deletion of spaces on resize </li>
           <li>Fixes forwarding of input while in normal mode (#1468)</li>
           <li>Fixes OSC-8 link id collision (#1499)</li>
           <li>Fixed overlap of glyphs for long codepoints (#1349)</li>
diff --git a/src/vtbackend/CellUtil.h b/src/vtbackend/CellUtil.h
index df516b22f4..8c1285338d 100644
--- a/src/vtbackend/CellUtil.h
+++ b/src/vtbackend/CellUtil.h
@@ -93,7 +93,7 @@ template <CellConcept Cell>
 template <CellConcept Cell>
 [[nodiscard]] inline bool empty(Cell const& cell) noexcept
 {
-    return (cell.codepointCount() == 0 || cell.codepoint(0) == 0x20) && !cell.imageFragment();
+    return (cell.codepointCount() == 0) && !cell.imageFragment();
 }
 
 template <CellConcept Cell>
diff --git a/src/vtbackend/Grid_test.cpp b/src/vtbackend/Grid_test.cpp
index 76bdad934a..2a9d0386d9 100644
--- a/src/vtbackend/Grid_test.cpp
+++ b/src/vtbackend/Grid_test.cpp
@@ -914,11 +914,26 @@ TEST_CASE("Grid resize with wrap and spaces", "[grid]")
     auto lineTrivial = Line<Cell>(LineFlag::None, trivial);
     grid.lineAt(LineOffset(0)) = lineTrivial;
 
-    {}(void) grid.resize(PageSize { LineCount(3), ColumnCount(6) }, CellLocation {}, false);
+    (void) grid.resize(PageSize { LineCount(3), ColumnCount(6) }, CellLocation {}, false);
     REQUIRE(grid.lineText(LineOffset(-1)) == "a a a ");
     REQUIRE(grid.lineText(LineOffset(0)) == "a     ");
     REQUIRE(grid.lineText(LineOffset(1)) == "      ");
-    {}(void) grid.resize(PageSize { LineCount(3), ColumnCount(7) }, CellLocation {}, false);
+    (void) grid.resize(PageSize { LineCount(3), ColumnCount(7) }, CellLocation {}, false);
+    REQUIRE(grid.lineText(LineOffset(0)) == "a a a a");
+    (void) grid.resize(PageSize { LineCount(3), ColumnCount(5) }, CellLocation {}, false);
+    REQUIRE(grid.lineText(LineOffset(-1)) == "a a a");
+    REQUIRE(grid.lineText(LineOffset(0)) == " a   ");
+    REQUIRE(grid.lineText(LineOffset(1)) == "     ");
+    (void) grid.resize(PageSize { LineCount(3), ColumnCount(4) }, CellLocation {}, false);
+    REQUIRE(grid.lineText(LineOffset(-1)) == "a a ");
+    REQUIRE(grid.lineText(LineOffset(0)) == "a a ");
+    REQUIRE(grid.lineText(LineOffset(1)) == "    ");
+    (void) grid.resize(PageSize { LineCount(3), ColumnCount(3) }, CellLocation {}, false);
+    REQUIRE(grid.lineText(LineOffset(-2)) == "a a");
+    REQUIRE(grid.lineText(LineOffset(-1)) == " a ");
+    REQUIRE(grid.lineText(LineOffset(0)) == "a  ");
+    REQUIRE(grid.lineText(LineOffset(1)) == "   ");
+    (void) grid.resize(PageSize { LineCount(3), ColumnCount(7) }, CellLocation {}, false);
     REQUIRE(grid.lineText(LineOffset(0)) == "a a a a");
 }
 
diff --git a/src/vtbackend/Line.cpp b/src/vtbackend/Line.cpp
index a8cc99dd3a..cda94adfab 100644
--- a/src/vtbackend/Line.cpp
+++ b/src/vtbackend/Line.cpp
@@ -56,14 +56,11 @@ typename Line<Cell>::InflatedBuffer Line<Cell>::reflow(ColumnCount newColumnCoun
                 buffer.erase(reflowStart, buffer.end());
                 assert(size() == newColumnCount);
 #if 0
-                if (removedColumns.size() > 0 &&
-                        std::any_of(removedColumns.begin(), removedColumns.end(),
-                            [](Cell const& x)
-                            {
-                                if (!x.empty())
-                                    fmt::print("non-empty cell in reflow: {}\n", x.toUtf8());
-                                return !x.empty();
-                            }))
+                if (removedColumns.size() > 0 && std::ranges::any_of(removedColumns, [](Cell const& x) {
+                        if (!x.empty())
+                            fmt::print("non-empty cell in reflow: {}\n", x.toUtf8());
+                        return !x.empty();
+                    }))
                     printf("Wrapping around\n");
 #endif
                 return removedColumns;