patch 8.0.0693: no terminal emulator support
Problem: No terminal emulator support. Cannot properly run commands in the
GUI. Cannot run a job interactively with an ssh connection.
Solution: Very early implementation of the :terminal command. Includes
libvterm converted to ANSI C. Many parts still missing.
diff --git a/src/libvterm/t/20state_wrapping.test b/src/libvterm/t/20state_wrapping.test
new file mode 100644
index 0000000..606fa06
--- /dev/null
+++ b/src/libvterm/t/20state_wrapping.test
@@ -0,0 +1,69 @@
+INIT
+UTF8 1
+WANTSTATE gm
+
+!79th Column
+PUSH "\e[75G"
+PUSH "A"x5
+ putglyph 0x41 1 0,74
+ putglyph 0x41 1 0,75
+ putglyph 0x41 1 0,76
+ putglyph 0x41 1 0,77
+ putglyph 0x41 1 0,78
+ ?cursor = 0,79
+
+!80th Column Phantom
+PUSH "A"
+ putglyph 0x41 1 0,79
+ ?cursor = 0,79
+
+!Line Wraparound
+PUSH "B"
+ putglyph 0x42 1 1,0
+ ?cursor = 1,1
+
+!Line Wraparound during combined write
+PUSH "\e[78G"
+PUSH "BBBCC"
+ putglyph 0x42 1 1,77
+ putglyph 0x42 1 1,78
+ putglyph 0x42 1 1,79
+ putglyph 0x43 1 2,0
+ putglyph 0x43 1 2,1
+ ?cursor = 2,2
+
+!DEC Auto Wrap Mode
+RESET
+PUSH "\e[?7l"
+PUSH "\e[75G"
+PUSH "D"x6
+ putglyph 0x44 1 0,74
+ putglyph 0x44 1 0,75
+ putglyph 0x44 1 0,76
+ putglyph 0x44 1 0,77
+ putglyph 0x44 1 0,78
+ putglyph 0x44 1 0,79
+ ?cursor = 0,79
+PUSH "D"
+ putglyph 0x44 1 0,79
+ ?cursor = 0,79
+PUSH "\e[?7h"
+
+!80th column causes linefeed on wraparound
+PUSH "\e[25;78HABC"
+ putglyph 0x41 1 24,77
+ putglyph 0x42 1 24,78
+ putglyph 0x43 1 24,79
+ ?cursor = 24,79
+PUSH "D"
+ moverect 1..25,0..80 -> 0..24,0..80
+ putglyph 0x44 1 24,0
+
+!80th column phantom linefeed phantom cancelled by explicit cursor move
+PUSH "\e[25;78HABC"
+ putglyph 0x41 1 24,77
+ putglyph 0x42 1 24,78
+ putglyph 0x43 1 24,79
+ ?cursor = 24,79
+PUSH "\e[25;1HD"
+ putglyph 0x44 1 24,0