Fixed: Fix ArrayIndexOutOfBoundsException thrown because length was l…

…ess than 0 when selecting text from terminal buffer

java.lang.ArrayIndexOutOfBoundsException: src.length=132 srcPos=90 dst.length=16 dstPos=0 length=-2
at java.lang.System.arraycopy(System.java:469)
at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:597)
at java.lang.StringBuilder.append(StringBuilder.java:191)
at com.termux.terminal.TerminalBuffer.getSelectedText(TerminalBuffer.java:97)
at com.termux.terminal.TerminalBuffer.getSelectedText(TerminalBuffer.java:57)
at com.termux.terminal.TerminalBuffer.getSelectedText(TerminalBuffer.java:53)
at com.termux.terminal.TerminalEmulator.getSelectedText(TerminalEmulator.java:2401)
at com.termux.view.textselection.TextSelectionCursorController$1.onActionItemClicked(TextSelectionCursorController.java:140)

terminal-emulator/src/main/java/com/termux/terminal/TerminalBuffer.java

@@ -93,8 +93,11 @@ public String getSelectedText(int selX1, int selY1, int selX2, int selY2, boolea
                     if (c != ' ') lastPrintingCharIndex = i;
                 }
             }
-            if (lastPrintingCharIndex != -1)
-                builder.append(line, x1Index, lastPrintingCharIndex - x1Index + 1);
+
+            int len = lastPrintingCharIndex - x1Index + 1;
+            if (lastPrintingCharIndex != -1 && len > 0)
+                builder.append(line, x1Index, len);
+
             boolean lineFillsWidth = lastPrintingCharIndex == x2Index - 1;
             if ((!joinBackLines || !rowLineWrap) && (!joinFullLines || !lineFillsWidth)
                 && row < selY2 && row < mScreenRows - 1) builder.append('\n');