From 85647b14e7492b1feccfb9fb3070a387d9eec248 Mon Sep 17 00:00:00 2001
From: Martin Valba <kailing2@live.com>
Date: Sun, 8 Jan 2023 20:42:34 +0200
Subject: [PATCH] Read description for info

# Commits from Termux for Terminal backend

##  Implement CSI 3 J - Clear transcript
* https://github.com/termux/termux-app/commit/2a36b915cbb201bda9b77431ae6d670961cee67a

## Avoid joining lines for shared transcript
* https://github.com/termux/termux-app/commit/370ac2bd8911b5632933975300e779f722ad03af

* All of this is needed so our terminal backend is up to date and works as needed
* If theres better method to give credit then lemme know.
---
 .../com/offsec/nhterm/backend/TerminalBuffer.java     | 11 ++++++++++-
 .../com/offsec/nhterm/backend/TerminalEmulator.java   |  2 +-
 .../nhterm/frontend/session/view/TerminalView.java    |  4 +++-
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/nhterm/src/main/java/com/offsec/nhterm/backend/TerminalBuffer.java b/nhterm/src/main/java/com/offsec/nhterm/backend/TerminalBuffer.java
index 1bbcc42..2e0a1f5 100644
--- a/nhterm/src/main/java/com/offsec/nhterm/backend/TerminalBuffer.java
+++ b/nhterm/src/main/java/com/offsec/nhterm/backend/TerminalBuffer.java
@@ -49,7 +49,15 @@ public final class TerminalBuffer {
     return getSelectedText(0, -getActiveTranscriptRows(), mColumns, mScreenRows).trim();
   }
 
+  public String getTranscriptTextWithoutJoinedLines() {
+    return getSelectedText(0, -getActiveTranscriptRows(), mColumns, mScreenRows, false).trim();
+  }
+
   public String getSelectedText(int selX1, int selY1, int selX2, int selY2) {
+    return getSelectedText(selX1, selY1, selX2, selY2, true);
+  }
+
+  public String getSelectedText(int selX1, int selY1, int selX2, int selY2, boolean joinBackLines) {
     final StringBuilder builder = new StringBuilder();
     final int columns = mColumns;
 
@@ -87,7 +95,8 @@ public final class TerminalBuffer {
       }
       if (lastPrintingCharIndex != -1)
         builder.append(line, x1Index, lastPrintingCharIndex - x1Index + 1);
-      if (!rowLineWrap && row < selY2 && row < mScreenRows - 1) builder.append('\n');
+      if ((!joinBackLines || !rowLineWrap)
+        && row < selY2 && row < mScreenRows - 1) builder.append('\n');
     }
     return builder.toString();
   }
diff --git a/nhterm/src/main/java/com/offsec/nhterm/backend/TerminalEmulator.java b/nhterm/src/main/java/com/offsec/nhterm/backend/TerminalEmulator.java
index 31ae3a3..4aceda7 100644
--- a/nhterm/src/main/java/com/offsec/nhterm/backend/TerminalEmulator.java
+++ b/nhterm/src/main/java/com/offsec/nhterm/backend/TerminalEmulator.java
@@ -1528,7 +1528,7 @@ public final class TerminalEmulator {
       case 'I': // Cursor Horizontal Forward Tabulation (CHT). Move the active position n tabs forward.
         setCursorCol(nextTabStop(getArg0(1)));
         break;
-      case 'J': // "${CSI}${0,1,2}J" - Erase in Display (ED)
+      case 'J': // "${CSI}${0,1,2,3}J" - Erase in Display (ED)
         // ED ignores the scrolling margins.
         switch (getArg0(0)) {
           case 0: // Erase from the active position to the end of the screen, inclusive (default).
diff --git a/nhterm/src/main/java/com/offsec/nhterm/frontend/session/view/TerminalView.java b/nhterm/src/main/java/com/offsec/nhterm/frontend/session/view/TerminalView.java
index a565f4a..8f5ed88 100644
--- a/nhterm/src/main/java/com/offsec/nhterm/frontend/session/view/TerminalView.java
+++ b/nhterm/src/main/java/com/offsec/nhterm/frontend/session/view/TerminalView.java
@@ -469,9 +469,11 @@ public final class TerminalView extends View {
       isScreenHeld = true;
     }
 
+    int rowsInHistory = mEmulator.getScreen().getActiveTranscriptRows();
+    if (mTopRow < -rowsInHistory) mTopRow = -rowsInHistory;
+
     if (mIsSelectingText || isScreenHeld) {
       // Do not scroll when selecting text.
-      int rowsInHistory = mEmulator.getScreen().getActiveTranscriptRows();
       int rowShift = mEmulator.getScrollCounter();
       if (-mTopRow + rowShift > rowsInHistory) {
         // .. unless we're hitting the end of history transcript, in which