patch 9.0.0774: the libvterm code is outdatedv9.0.0774

Problem:    The libvterm code is outdated.
Solution:   Include libvterm changes from revision 802 to 817.  Revert some
            changes made for C89.

24 files changed, 655 insertions, 254 deletions

diff --git a/src/libvterm/CONTRIBUTING b/src/libvterm/CONTRIBUTING
index 2100d1e510..e9a8f0c331 100644
--- a/src/libvterm/CONTRIBUTING
+++ b/src/libvterm/CONTRIBUTING
@@ -6,8 +6,8 @@ The main resources for this library are:
   Launchpad
     https://launchpad.net/libvterm
 
-  Freenode:
-    ##tty or #tickit on irc.freenode.net
+  IRC:
+    ##tty or #tickit on irc.libera.chat
 
   Email:
     Paul "LeoNerd" Evans <leonerd@leonerd.org.uk>
diff --git a/src/libvterm/Makefile b/src/libvterm/Makefile
index 2f83e0d68c..ba4a3157ed 100644
--- a/src/libvterm/Makefile
+++ b/src/libvterm/Makefile
@@ -37,7 +37,7 @@ INCFILES=$(TBLFILES:.tbl=.inc)
 HFILES_INT=$(sort $(wildcard src/*.h)) $(HFILES)
 
 VERSION_MAJOR=0
-VERSION_MINOR=2
+VERSION_MINOR=3
 
 VERSION_CURRENT=0
 VERSION_REVISION=0
diff --git a/src/libvterm/README b/src/libvterm/README
index 8e9341d070..264128445d 100644
--- a/src/libvterm/README
+++ b/src/libvterm/README
@@ -7,8 +7,11 @@ The original can be found:
 	https://github.com/neovim/libvterm
 
 Modifications:
-- Add a .gitignore file.
-- Convert some code from C99 to C90.
+- revisions up to 817 have been included
+- Added a .gitignore file.
+- use TRUE and FALSE instead of true and false
+- use int or unsigned int instead of bool
+- Converted some code from C99 to C90.
 - Other changes to support embedding in Vim.
 
 To get the latest version of libvterm you need the "bzr" command and do:
diff --git a/src/libvterm/doc/seqs.txt b/src/libvterm/doc/seqs.txt
index 02a9fe51f6..27f28b91b6 100644
--- a/src/libvterm/doc/seqs.txt
+++ b/src/libvterm/doc/seqs.txt
@@ -122,6 +122,7 @@ x = xterm
 123x   CSI l            = RM, Reset mode
 123x   CSI ? l          = DECRM, DEC reset mode
 123x   CSI m            = SGR, Set Graphic Rendition
+       CSI ? m          = DECSGR, private Set Graphic Rendition
 123x   CSI   n          = DSR, Device Status Report
  23x       5            =   operating status
  23x       6            =   CPR = cursor position
@@ -198,6 +199,9 @@ x = xterm
    x   SGR 40-47        = Background ANSI
    x   SGR 48           = Background alternative palette
    x   SGR 49           = Background default
+       SGR 73           = Superscript on
+       SGR 74           = Subscript on
+       SGR 75           = Superscript/subscript off
    x   SGR 90-97        = Foreground ANSI high-intensity
    x   SGR 100-107      = Background ANSI high-intensity
 
diff --git a/src/libvterm/include/vterm.h b/src/libvterm/include/vterm.h
index 21295a62a9..e5887c8714 100644
--- a/src/libvterm/include/vterm.h
+++ b/src/libvterm/include/vterm.h
@@ -12,16 +12,17 @@ extern "C" {
 
 #include "vterm_keycodes.h"
 
+// VIM: use TRUE and FALSE instead of true and false
 #define TRUE 1
 #define FALSE 0
 
-// from stdint.h
+// VIM: from stdint.h
 typedef unsigned char		uint8_t;
 typedef unsigned short		uint16_t;
 typedef unsigned int		uint32_t;
 
 #define VTERM_VERSION_MAJOR 0
-#define VTERM_VERSION_MINOR 2
+#define VTERM_VERSION_MINOR 3
 
 #define VTERM_CHECK_VERSION \
         vterm_check_version(VTERM_VERSION_MAJOR, VTERM_VERSION_MINOR)
@@ -131,7 +132,7 @@ typedef enum {
   VTERM_COLOR_DEFAULT_MASK = 0x06,
 
   /**
-   * If set, indicates that the color is invalid.
+   * VIM: If set, indicates that the color is invalid.
    */
   VTERM_COLOR_INVALID = 0x08
 } VTermColorType;
@@ -172,6 +173,7 @@ typedef enum {
  */
 #define VTERM_COLOR_IS_INVALID(col) (!!((col)->type & VTERM_COLOR_INVALID))
 
+// VIM: this was a union, but that doesn't always work.
 typedef struct {
   /**
    * Tag indicating which member is actually valid.
@@ -237,6 +239,8 @@ typedef enum {
   VTERM_ATTR_FONT,       // number: 10-19
   VTERM_ATTR_FOREGROUND, // color:  30-39 90-97
   VTERM_ATTR_BACKGROUND, // color:  40-49 100-107
+  VTERM_ATTR_SMALL,      // bool:   73, 74, 75
+  VTERM_ATTR_BASELINE,   // number: 73, 74, 75
 
   VTERM_N_ATTRS
 } VTermAttr;
@@ -251,7 +255,7 @@ typedef enum {
   VTERM_PROP_REVERSE,           // bool
   VTERM_PROP_CURSORSHAPE,       // number
   VTERM_PROP_MOUSE,             // number
-  VTERM_PROP_CURSORCOLOR,       // string
+  VTERM_PROP_CURSORCOLOR,       // VIM - string
 
   VTERM_N_PROPS
 } VTermProp;
@@ -312,7 +316,6 @@ typedef struct {
   void  (*free)(void *ptr, void *allocdata);
 } VTermAllocatorFunctions;
 
-/* A convenient shortcut for default cases */
 void vterm_check_version(int major, int minor);
 
 struct VTermBuilder {
@@ -333,7 +336,6 @@ VTerm *vterm_build(const struct VTermBuilder *builder);
 /* A convenient shortcut for default cases */
 // Allocate and initialize a new terminal with default allocators.
 VTerm *vterm_new(int rows, int cols);
-
 /* These shortcuts are generally discouraged in favour of just using vterm_build() */
 
 // Allocate and initialize a new terminal with specified allocators.
@@ -396,6 +398,7 @@ void vterm_mouse_button(VTerm *vt, int button, int pressed, VTermModifier mod);
 #define CSI_ARG(a)          ((a) & CSI_ARG_MASK)
 
 /* Can't use -1 to indicate a missing argument; use this instead */
+// VIM: changed 31 to 30 to avoid an overflow warning
 #define CSI_ARG_MISSING ((1<<30)-1)
 
 #define CSI_ARG_IS_MISSING(a) (CSI_ARG(a) == CSI_ARG_MISSING)
@@ -436,8 +439,10 @@ typedef struct {
   int (*bell)(void *user);
   int (*resize)(int rows, int cols, VTermStateFields *fields, void *user);
   int (*setlineinfo)(int row, const VTermLineInfo *newinfo, const VTermLineInfo *oldinfo, void *user);
+  int (*sb_clear)(void *user);
 } VTermStateCallbacks;
 
+// VIM: added
 typedef struct {
   VTermPos pos;
   int	   buttons;
@@ -478,6 +483,7 @@ void *vterm_state_get_unrecognised_fbdata(VTermState *state);
 void vterm_state_reset(VTermState *state, int hard);
 
 void vterm_state_get_cursorpos(const VTermState *state, VTermPos *cursorpos);
+// VIM: added
 void vterm_state_get_mousestate(const VTermState *state, VTermMouseState *mousestate);
 void vterm_state_get_default_colors(const VTermState *state, VTermColor *default_fg, VTermColor *default_bg);
 void vterm_state_get_palette_color(const VTermState *state, int index, VTermColor *col);
@@ -522,6 +528,8 @@ typedef struct {
     unsigned int font      : 4; /* 0 to 9 */
     unsigned int dwl       : 1; /* On a DECDWL or DECDHL line */
     unsigned int dhl       : 2; /* On a DECDHL line (1=top 2=bottom) */
+    unsigned int small     : 1;
+    unsigned int baseline  : 2;
 } VTermScreenCellAttrs;
 
 enum {
@@ -531,6 +539,12 @@ enum {
   VTERM_UNDERLINE_CURLY,
 };
 
+enum {
+  VTERM_BASELINE_NORMAL,
+  VTERM_BASELINE_RAISE,
+  VTERM_BASELINE_LOWER,
+};
+
 typedef struct {
   uint32_t chars[VTERM_MAX_CHARS_PER_CELL];
   char     width;
@@ -551,6 +565,7 @@ typedef struct {
   // Return value is unused.
   int (*sb_pushline)(int cols, const VTermScreenCell *cells, void *user);
   int (*sb_popline)(int cols, VTermScreenCell *cells, void *user);
+  int (*sb_clear)(void* user);
 } VTermScreenCallbacks;
 
 // Return the screen of the vterm.
@@ -566,6 +581,11 @@ void *vterm_screen_get_cbdata(VTermScreen *screen);
 void  vterm_screen_set_unrecognised_fallbacks(VTermScreen *screen, const VTermStateFallbacks *fallbacks, void *user);
 void *vterm_screen_get_unrecognised_fbdata(VTermScreen *screen);
 
+void vterm_screen_enable_reflow(VTermScreen *screen, int reflow);
+
+// Back-compat alias for the brief time it was in 0.3-RC1
+#define vterm_screen_set_reflow  vterm_screen_enable_reflow
+
 // Enable support for using the alternate screen if "altscreen" is non-zero.
 // Before that switching to the alternate screen won't work.
 // Calling with "altscreen" zero has no effect.
@@ -606,8 +626,10 @@ typedef enum {
   VTERM_ATTR_FOREGROUND_MASK = 1 << 7,
   VTERM_ATTR_BACKGROUND_MASK = 1 << 8,
   VTERM_ATTR_CONCEAL_MASK    = 1 << 9,
+  VTERM_ATTR_SMALL_MASK      = 1 << 10,
+  VTERM_ATTR_BASELINE_MASK   = 1 << 11,
 
-  VTERM_ALL_ATTRS_MASK = (1 << 10) - 1
+  VTERM_ALL_ATTRS_MASK = (1 << 12) - 1
 } VTermAttrMask;
 
 int vterm_screen_get_attrs_extent(const VTermScreen *screen, VTermRect *extent, VTermPos pos, VTermAttrMask attrs);
diff --git a/src/libvterm/src/encoding.c b/src/libvterm/src/encoding.c
index 694ed6a0ca..817344f333 100644
--- a/src/libvterm/src/encoding.c
+++ b/src/libvterm/src/encoding.c
@@ -49,6 +49,7 @@ static void decode_utf8(VTermEncoding *enc UNUSED, void *data_,
       if(data->bytes_remaining) {
         data->bytes_remaining = 0;
         cp[(*cpi)++] = UNICODE_INVALID;
+	// VIM: avoid going over the end
 	if (*cpi >= cplen)
 	  break;
       }
@@ -226,8 +227,7 @@ encodings[] = {
 /* This ought to be INTERNAL but isn't because it's used by unit testing */
 VTermEncoding *vterm_lookup_encoding(VTermEncodingType type, char designation)
 {
-  int i;
-  for(i = 0; encodings[i].designation; i++)
+  for(int i = 0; encodings[i].designation; i++)
     if(encodings[i].type == type && encodings[i].designation == designation)
       return encodings[i].enc;
   return NULL;
diff --git a/src/libvterm/src/keyboard.c b/src/libvterm/src/keyboard.c
index 87288fe970..c04984abab 100644
--- a/src/libvterm/src/keyboard.c
+++ b/src/libvterm/src/keyboard.c
@@ -4,6 +4,7 @@
 
 #include "utf8.h"
 
+// VIM: added
 int vterm_is_modify_other_keys(VTerm *vt)
 {
   return vt->state->mode.modify_other_keys;
@@ -12,8 +13,7 @@ int vterm_is_modify_other_keys(VTerm *vt)
 
 void vterm_keyboard_unichar(VTerm *vt, uint32_t c, VTermModifier mod)
 {
-  int needs_CSIu;
-
+  // VIM: added modifyOtherKeys support
   if (vt->state->mode.modify_other_keys && mod != 0) {
     vterm_push_output_sprintf_ctrl(vt, C1_CSI, "27;%d;%d~", mod+1, c);
     return;
@@ -33,6 +33,7 @@ void vterm_keyboard_unichar(VTerm *vt, uint32_t c, VTermModifier mod)
     return;
   }
 
+  int needs_CSIu;
   switch(c) {
     /* Special Ctrl- letters that can't be represented elsewise */
     case 'i': case 'j': case 'm': case '[':
@@ -93,12 +94,12 @@ static keycodes_s keycodes[] = {
   { KEYCODE_CSI_CURSOR, 'D', 0 }, // LEFT
   { KEYCODE_CSI_CURSOR, 'C', 0 }, // RIGHT
 
-  { KEYCODE_CSINUM,     '~', 2 }, // INS
-  { KEYCODE_CSINUM,     '~', 3 }, // DEL
+  { KEYCODE_CSINUM, '~', 2 },  // INS
+  { KEYCODE_CSINUM, '~', 3 },  // DEL
   { KEYCODE_CSI_CURSOR, 'H', 0 }, // HOME
   { KEYCODE_CSI_CURSOR, 'F', 0 }, // END
-  { KEYCODE_CSINUM,     '~', 5 }, // PAGEUP
-  { KEYCODE_CSINUM,     '~', 6 }, // PAGEDOWN
+  { KEYCODE_CSINUM, '~', 5 },  // PAGEUP
+  { KEYCODE_CSINUM, '~', 6 },  // PAGEDOWN
 };
 
 static keycodes_s keycodes_fn[] = {
@@ -107,14 +108,14 @@ static keycodes_s keycodes_fn[] = {
   { KEYCODE_SS3,	'Q', 0 }, // F2
   { KEYCODE_SS3,	'R', 0 }, // F3
   { KEYCODE_SS3,	'S', 0 }, // F4
-  { KEYCODE_CSINUM,     '~', 15 }, // F5
-  { KEYCODE_CSINUM,     '~', 17 }, // F6
-  { KEYCODE_CSINUM,     '~', 18 }, // F7
-  { KEYCODE_CSINUM,     '~', 19 }, // F8
-  { KEYCODE_CSINUM,     '~', 20 }, // F9
-  { KEYCODE_CSINUM,     '~', 21 }, // F10
-  { KEYCODE_CSINUM,     '~', 23 }, // F11
-  { KEYCODE_CSINUM,     '~', 24 }, // F12
+  { KEYCODE_CSINUM, '~', 15 }, // F5
+  { KEYCODE_CSINUM, '~', 17 }, // F6
+  { KEYCODE_CSINUM, '~', 18 }, // F7
+  { KEYCODE_CSINUM, '~', 19 }, // F8
+  { KEYCODE_CSINUM, '~', 20 }, // F9
+  { KEYCODE_CSINUM, '~', 21 }, // F10
+  { KEYCODE_CSINUM, '~', 23 }, // F11
+  { KEYCODE_CSINUM, '~', 24 }, // F12
 };
 
 static keycodes_s keycodes_kp[] = {
@@ -140,11 +141,10 @@ static keycodes_s keycodes_kp[] = {
 
 void vterm_keyboard_key(VTerm *vt, VTermKey key, VTermModifier mod)
 {
-  keycodes_s k;
-
   if(key == VTERM_KEY_NONE)
     return;
 
+  keycodes_s k;
   if(key < VTERM_KEY_FUNCTION_0) {
     if(key >= sizeof(keycodes)/sizeof(keycodes[0]))
       return;
diff --git a/src/libvterm/src/parser.c b/src/libvterm/src/parser.c
index 0d4422cf49..d4cd0dc477 100644
--- a/src/libvterm/src/parser.c
+++ b/src/libvterm/src/parser.c
@@ -142,7 +142,6 @@ size_t vterm_input_write(VTerm *vt, const char *bytes, size_t len)
   for( ; pos < len; pos++) {
     unsigned char c = bytes[pos];
     int c1_allowed = !vt->mode.utf8;
-    size_t string_len;
 
     if(c == 0x00 || c == 0x7f) { // NUL, DEL
       if(IS_STRING_STATE()) {
@@ -187,7 +186,7 @@ size_t vterm_input_write(VTerm *vt, const char *bytes, size_t len)
     }
     // else fallthrough
 
-    string_len = bytes + pos - string_start;
+    size_t string_len = bytes + pos - string_start;
 
     if(vt->parser.in_esc) {
       // Hoist an ESC letter into a C1 if we're not in a string mode
@@ -247,7 +246,7 @@ size_t vterm_input_write(VTerm *vt, const char *bytes, size_t len)
       vt->parser.v.csi.argi++;
       vt->parser.intermedlen = 0;
       vt->parser.state = CSI_INTERMED;
-      // fallthrough
+      // FALLTHROUGH
     case CSI_INTERMED:
       if(is_intermed(c)) {
         if(vt->parser.intermedlen < INTERMED_MAX-1)
diff --git a/src/libvterm/src/pen.c b/src/libvterm/src/pen.c
index c5a0b71c5d..1c6cd4e488 100644
--- a/src/libvterm/src/pen.c
+++ b/src/libvterm/src/pen.c
@@ -44,6 +44,7 @@ static int ramp24[] = {
 
 static void lookup_default_colour_ansi(long idx, VTermColor *col)
 {
+  // VIM: store both RGB color and index
   vterm_color_rgb(
       col,
       ansi_colors[idx].red, ansi_colors[idx].green, ansi_colors[idx].blue);
@@ -161,27 +162,27 @@ static void set_pen_col_ansi(VTermState *state, VTermAttr attr, long col)
 
 INTERNAL void vterm_state_newpen(VTermState *state)
 {
-  int col;
-
   // 90% grey so that pure white is brighter
   vterm_color_rgb(&state->default_fg, 240, 240, 240);
   vterm_color_rgb(&state->default_bg, 0, 0, 0);
   vterm_state_set_default_colors(state, &state->default_fg, &state->default_bg);
 
-  for(col = 0; col < 16; col++)
+  for(int col = 0; col < 16; col++)
     lookup_default_colour_ansi(col, &state->colors[col]);
 }
 
 INTERNAL void vterm_state_resetpen(VTermState *state)
 {
   state->pen.bold = 0;      setpenattr_bool(state, VTERM_ATTR_BOLD, 0);
-  state->pen.underline = 0; setpenattr_int( state, VTERM_ATTR_UNDERLINE, 0);
+  state->pen.underline = 0; setpenattr_int (state, VTERM_ATTR_UNDERLINE, 0);
   state->pen.italic = 0;    setpenattr_bool(state, VTERM_ATTR_ITALIC, 0);
   state->pen.blink = 0;     setpenattr_bool(state, VTERM_ATTR_BLINK, 0);
   state->pen.reverse = 0;   setpenattr_bool(state, VTERM_ATTR_REVERSE, 0);
   state->pen.conceal = 0;   setpenattr_bool(state, VTERM_ATTR_CONCEAL, 0);
   state->pen.strike = 0;    setpenattr_bool(state, VTERM_ATTR_STRIKE, 0);
-  state->pen.font = 0;      setpenattr_int( state, VTERM_ATTR_FONT, 0);
+  state->pen.font = 0;      setpenattr_int (state, VTERM_ATTR_FONT, 0);
+  state->pen.small = 0;     setpenattr_bool(state, VTERM_ATTR_SMALL, 0);
+  state->pen.baseline = 0;  setpenattr_int (state, VTERM_ATTR_BASELINE, 0);
 
   state->pen.fg = state->default_fg;  setpenattr_col(state, VTERM_ATTR_FOREGROUND, state->default_fg);
   state->pen.bg = state->default_bg;  setpenattr_col(state, VTERM_ATTR_BACKGROUND, state->default_bg);
@@ -195,14 +196,17 @@ INTERNAL void vterm_state_savepen(VTermState *state, int save)
   else {
     state->pen = state->saved.pen;
 
-    setpenattr_bool(state, VTERM_ATTR_BOLD,       state->pen.bold);
-    setpenattr_int( state, VTERM_ATTR_UNDERLINE,  state->pen.underline);
-    setpenattr_bool(state, VTERM_ATTR_ITALIC,     state->pen.italic);
-    setpenattr_bool(state, VTERM_ATTR_BLINK,      state->pen.blink);
-    setpenattr_bool(state, VTERM_ATTR_REVERSE,    state->pen.reverse);
-    setpenattr_bool(state, VTERM_ATTR_CONCEAL,    state->pen.conceal);
-    setpenattr_bool(state, VTERM_ATTR_STRIKE,     state->pen.strike);
-    setpenattr_int( state, VTERM_ATTR_FONT,       state->pen.font);
+    setpenattr_bool(state, VTERM_ATTR_BOLD,      state->pen.bold);
+    setpenattr_int (state, VTERM_ATTR_UNDERLINE, state->pen.underline);
+    setpenattr_bool(state, VTERM_ATTR_ITALIC,    state->pen.italic);
+    setpenattr_bool(state, VTERM_ATTR_BLINK,     state->pen.blink);
+    setpenattr_bool(state, VTERM_ATTR_REVERSE,   state->pen.reverse);
+    setpenattr_bool(state, VTERM_ATTR_CONCEAL,   state->pen.conceal);
+    setpenattr_bool(state, VTERM_ATTR_STRIKE,    state->pen.strike);
+    setpenattr_int (state, VTERM_ATTR_FONT,      state->pen.font);
+    setpenattr_bool(state, VTERM_ATTR_SMALL,     state->pen.small);
+    setpenattr_int (state, VTERM_ATTR_BASELINE,  state->pen.baseline);
+
     setpenattr_col( state, VTERM_ATTR_FOREGROUND, state->pen.fg);
     setpenattr_col( state, VTERM_ATTR_BACKGROUND, state->pen.bg);
   }
@@ -447,6 +451,18 @@ INTERNAL void vterm_state_setpen(VTermState *state, const long args[], int argco
       setpenattr_col(state, VTERM_ATTR_BACKGROUND, state->pen.bg);
       break;
 
+    case 73: // Superscript
+    case 74: // Subscript
+    case 75: // Superscript/subscript off
+      state->pen.small = (arg != 75);
+      state->pen.baseline =
+        (arg == 73) ? VTERM_BASELINE_RAISE :
+        (arg == 74) ? VTERM_BASELINE_LOWER :
+                      VTERM_BASELINE_NORMAL;
+      setpenattr_bool(state, VTERM_ATTR_SMALL,    state->pen.small);
+      setpenattr_int (state, VTERM_ATTR_BASELINE, state->pen.baseline);
+      break;
+
     case 90: case 91: case 92: case 93:
     case 94: case 95: case 96: case 97: // Foreground colour high-intensity palette
       value = CSI_ARG(args[argi]) - 90 + 8;
@@ -544,6 +560,13 @@ INTERNAL int vterm_state_getpen(VTermState *state, long args[], int argcount UNU
 
   argi = vterm_state_getpen_color(&state->pen.bg, argi, args, FALSE);
 
+  if(state->pen.small) {
+    if(state->pen.baseline == VTERM_BASELINE_RAISE)
+      args[argi++] = 73;
+    else if(state->pen.baseline == VTERM_BASELINE_LOWER)
+      args[argi++] = 74;
+  }
+
   return argi;
 }
 
@@ -590,6 +613,14 @@ int vterm_state_get_penattr(const VTermState *state, VTermAttr attr, VTermValue
     val->color = state->pen.bg;
     return 1;
 
+  case VTERM_ATTR_SMALL:
+    val->boolean = state->pen.small;
+    return 1;
+
+  case VTERM_ATTR_BASELINE:
+    val->number = state->pen.baseline;
+    return 1;
+
   case VTERM_N_ATTRS:
     return 0;
   }
diff --git a/src/libvterm/src/screen.c b/src/libvterm/src/screen.c
index 25ddb13991..069306ab95 100644
--- a/src/libvterm/src/screen.c
+++ b/src/libvterm/src/screen.c
@@ -10,6 +10,8 @@
 #define UNICODE_SPACE 0x20
 #define UNICODE_LINEFEED 0x0a
 
+#undef DEBUG_REFLOW
+
 /* State of the pen at some moment in time, also used in a cell */
 typedef struct
 {
@@ -24,6 +26,8 @@ typedef struct
   unsigned int conceal   : 1;
   unsigned int strike    : 1;
   unsigned int font      : 4; /* 0 to 9 */
+  unsigned int small     : 1;
+  unsigned int baseline  : 2;
 
   /* Extra state storage that isn't strictly pen-related */
   unsigned int protected_cell : 1;
@@ -54,7 +58,9 @@ struct VTermScreen
 
   int rows;
   int cols;
-  int global_reverse;
+
+  unsigned int global_reverse : 1;
+  unsigned int reflow : 1;
 
   /* Primary and Altscreen. buffers[1] is lazily allocated as needed */
   ScreenCell *buffers[2];
@@ -88,11 +94,9 @@ static ScreenCell *getcell(const VTermScreen *screen, int row, int col)
 static ScreenCell *alloc_buffer(VTermScreen *screen, int rows, int cols)
 {
   ScreenCell *new_buffer = vterm_allocator_malloc(screen->vt, sizeof(ScreenCell) * rows * cols);
-  int row;
-  int col;
 
-  for(row = 0; row < rows; row++) {
-    for(col = 0; col < cols; col++) {
+  for(int row = 0; row < rows; row++) {
+    for(int col = 0; col < cols; col++) {
       clearcell(screen, &new_buffer[row * cols + col]);
     }
   }
@@ -168,16 +172,13 @@ static void damagescreen(VTermScreen *screen)
 
 static int putglyph(VTermGlyphInfo *info, VTermPos pos, void *user)
 {
-  int i;
-  int col;
-  VTermRect rect;
-
   VTermScreen *screen = user;
   ScreenCell *cell = getcell(screen, pos.row, pos.col);
 
   if(!cell)
     return 0;
 
+  int i;
   for(i = 0; i < VTERM_MAX_CHARS_PER_CELL && info->chars[i]; i++) {
     cell->chars[i] = info->chars[i];
     cell->pen = screen->pen;
@@ -185,7 +186,7 @@ static int putglyph(VTermGlyphInfo *info, VTermPos pos, void *user)
   if(i < VTERM_MAX_CHARS_PER_CELL)
     cell->chars[i] = 0;
 
-  for(col = 1; col < info->width; col++)
+  for(int col = 1; col < info->width; col++)
   {
     ScreenCell *onecell = getcell(screen, pos.row, pos.col + col);
     if (onecell == NULL)
@@ -193,6 +194,7 @@ static int putglyph(VTermGlyphInfo *info, VTermPos pos, void *user)
     onecell->chars[0] = (uint32_t)-1;
   }
 
+  VTermRect rect;
   rect.start_row = pos.row;
   rect.end_row   = pos.row+1;
   rect.start_col = pos.col;
@@ -225,34 +227,30 @@ static int moverect_internal(VTermRect dest, VTermRect src, void *user)
      dest.start_row == 0 && dest.start_col == 0 &&        // starts top-left corner
      dest.end_col == screen->cols &&                      // full width
      screen->buffer == screen->buffers[BUFIDX_PRIMARY]) { // not altscreen
-    int row;
-    for(row = 0; row < src.start_row; row++)
+    for(int row = 0; row < src.start_row; row++)
       sb_pushline_from_row(screen, row);
   }
 
-  {
-    int cols = src.end_col - src.start_col;
-    int downward = src.start_row - dest.start_row;
-    int init_row, test_row, inc_row;
-    int row;
-
-    if(downward < 0) {
-      init_row = dest.end_row - 1;
-      test_row = dest.start_row - 1;
-      inc_row  = -1;
-    }
-    else {
-      init_row = dest.start_row;
-      test_row = dest.end_row;
-      inc_row  = +1;
-    }
+  int cols = src.end_col - src.start_col;
+  int downward = src.start_row - dest.start_row;
 
-    for(row = init_row; row != test_row; row += inc_row)
-      memmove(getcell(screen, row, dest.start_col),
-	      getcell(screen, row + downward, src.start_col),
-	      cols * sizeof(ScreenCell));
+  int init_row, test_row, inc_row;
+  if(downward < 0) {
+    init_row = dest.end_row - 1;
+    test_row = dest.start_row - 1;
+    inc_row  = -1;
+  }
+  else {
+    init_row = dest.start_row;
+    test_row = dest.end_row;
+    inc_row  = +1;
   }
 
+  for(int row = init_row; row != test_row; row += inc_row)
+    memmove(getcell(screen, row, dest.start_col),
+            getcell(screen, row + downward, src.start_col),
+            cols * sizeof(ScreenCell));
+
   return 1;
 }
 
@@ -277,12 +275,11 @@ static int moverect_user(VTermRect dest, VTermRect src, void *user)
 static int erase_internal(VTermRect rect, int selective, void *user)
 {
   VTermScreen *screen = user;
-  int row, col;
 
-  for(row = rect.start_row; row < screen->state->rows && row < rect.end_row; row++) {
+  for(int row = rect.start_row; row < screen->state->rows && row < rect.end_row; row++) {
     const VTermLineInfo *info = vterm_state_get_lineinfo(screen->state, row);
 
-    for(col = rect.start_col; col < rect.end_col; col++) {
+    for(int col = rect.start_col; col < rect.end_col; col++) {
       ScreenCell *cell = getcell(screen, row, col);
 
       if (cell == NULL)
@@ -448,6 +445,12 @@ static int setpenattr(VTermAttr attr, VTermValue *val, void *user)
   case VTERM_ATTR_BACKGROUND:
     screen->pen.bg = val->color;
     return 1;
+  case VTERM_ATTR_SMALL:
+    screen->pen.small = val->boolean;
+    return 1;
+  case VTERM_ATTR_BASELINE:
+    screen->pen.baseline = val->number;
+    return 1;
 
   case VTERM_N_ATTRS:
     return 0;
@@ -496,6 +499,18 @@ static int bell(void *user)
   return 0;
 }
 
+/* How many cells are non-blank
+ * Returns the position of the first blank cell in the trailing blank end */
+static int line_popcount(ScreenCell *buffer, int row, int rows UNUSED, int cols)
+{
+  int col = cols - 1;
+  while(col >= 0 && buffer[row * cols + col].chars[0] == 0)
+    col--;
+  return col + 1;
+}
+
+#define REFLOW (screen->reflow)
+
 static void resize_buffer(VTermScreen *screen, int bufidx, int new_rows, int new_cols, int active, VTermStateFields *statefields)
 {
   int old_rows = screen->rows;
@@ -510,33 +525,150 @@ static void resize_buffer(VTermScreen *screen, int bufidx, int new_rows, int new
   // Find the final row of old buffer content
   int old_row = old_rows - 1;
   int new_row = new_rows - 1;
-  int col;
 
-  while(new_row >= 0 && old_row >= 0) {
-    for(col = 0; col < old_cols && col < new_cols; col++)
-      new_buffer[new_row * new_cols + col] = old_buffer[old_row * old_cols + col];
-    for( ; col < new_cols; col++)
-      clearcell(screen, &new_buffer[new_row * new_cols + col]);
+  VTermPos old_cursor = statefields->pos;
+  VTermPos new_cursor = { -1, -1 };
 
-    new_lineinfo[new_row] = old_lineinfo[old_row];
+#ifdef DEBUG_REFLOW
+  fprintf(stderr, "Resizing from %dx%d to %dx%d; cursor was at (%d,%d)\n",
+      old_cols, old_rows, new_cols, new_rows, old_cursor.col, old_cursor.row);
+#endif
 
-    old_row--;
-    new_row--;
+  /* Keep track of the final row that is knonw to be blank, so we know what
+   * spare space we have for scrolling into
+   */
+  int final_blank_row = new_rows;
+
+  while(old_row >= 0) {
+    int old_row_end = old_row;
+    /* TODO: Stop if dwl or dhl */
+    while(REFLOW && old_lineinfo && old_row >= 0 && old_lineinfo[old_row].continuation)
+      old_row--;
+    int old_row_start = old_row;
+
+    int width = 0;
+    for(int row = old_row_start; row <= old_row_end; row++) {
+      if(REFLOW && row < (old_rows - 1) && old_lineinfo[row + 1].continuation)
+        width += old_cols;
+      else
+        width += line_popcount(old_buffer, row, old_rows, old_cols);
+    }
+
+    if(final_blank_row == (new_row + 1) && width == 0)
+      final_blank_row = new_row;
+
+    int new_height = REFLOW
+      ? width ? (width + new_cols - 1) / new_cols : 1
+      : 1;
+
+    int new_row_end = new_row;
+    int new_row_start = new_row - new_height + 1;
+
+    old_row = old_row_start;
+    int old_col = 0;
+
+    int spare_rows = new_rows - final_blank_row;
+
+    if(new_row_start < 0 && /* we'd fall off the top */
+        spare_rows >= 0 && /* we actually have spare rows */
+        (!active || new_cursor.row == -1 || (new_cursor.row - new_row_start) < new_rows))
+    {
+      /* Attempt to scroll content down into the blank rows at the bottom to
+       * make it fit
+       */
+      int downwards = -new_row_start;
+      if(downwards > spare_rows)
+        downwards = spare_rows;
+      int rowcount = new_rows - downwards;
+
+#ifdef DEBUG_REFLOW
+      fprintf(stderr, "  scroll %d rows +%d downwards\n", rowcount, downwards);
+#endif
+
+      memmove(&new_buffer[downwards * new_cols], &new_buffer[0],   rowcount * new_cols * sizeof(ScreenCell));
+      memmove(&new_lineinfo[downwards],          &new_lineinfo[0], rowcount            * sizeof(new_lineinfo[0]));
+
+      new_row += downwards;
+      new_row_start += downwards;
+      new_row_end += downwards;
 
-    if(new_row < 0 && old_row >= 0 &&
-        new_buffer[(new_rows - 1) * new_cols].chars[0] == 0 &&
-        (!active || statefields->pos.row < (new_rows - 1))) {
-      int moverows = new_rows - 1;
-      memmove(&new_buffer[1 * new_cols], &new_buffer[0], moverows * new_cols * sizeof(ScreenCell));
+      if(new_cursor.row >= 0)
+        new_cursor.row += downwards;
 
-      new_row++;
+      final_blank_row += downwards;
     }
+
+#ifdef DEBUG_REFLOW
+    fprintf(stderr, "  rows [%d..%d] <- [%d..%d] width=%d\n",
+        new_row_start, new_row_end, old_row_start, old_row_end, width);
+#endif
+
+    if(new_row_start < 0)
+      break;
+
+    for(new_row = new_row_start, old_row = old_row_start; new_row <= new_row_end; new_row++) {
+      int count = width >= new_cols ? new_cols : width;
+      width -= count;
+
+      int new_col = 0;
+
+      while(count) {
+        /* TODO: This could surely be done a lot faster by memcpy()'ing the entire range */
+        new_buffer[new_row * new_cols + new_col] = old_buffer[old_row * old_cols + old_col];
+
+        if(old_cursor.row == old_row && old_cursor.col == old_col)
+          new_cursor.row = new_row, new_cursor.col = new_col;
+
+        old_col++;
+        if(old_col == old_cols) {
+          old_row++;
+
+          if(!REFLOW) {
+            new_col++;
+            break;
+          }
+          old_col = 0;
+        }
+
+        new_col++;
+        count--;
+      }
+
+      if(old_cursor.row == old_row && old_cursor.col >= old_col) {
+        new_cursor.row = new_row, new_cursor.col = (old_cursor.col - old_col + new_col);
+        if(new_cursor.col >= new_cols)
+          new_cursor.col = new_cols-1;
+      }
+
+      while(new_col < new_cols) {
+        clearcell(screen, &new_buffer[new_row * new_cols + new_col]);
+        new_col++;
+      }
+
+      new_lineinfo[new_row].continuation = (new_row > new_row_start);
+    }
+
+    old_row = old_row_start - 1;
+    new_row = new_row_start - 1;
+  }
+
+  if(old_cursor.row <= old_row) {
+    /* cursor would have moved entirely off the top of the screen; lets just
+     * bring it within range */
+    new_cursor.row = 0, new_cursor.col = old_cursor.col;
+    if(new_cursor.col >= new_cols)
+      new_cursor.col = new_cols-1;
+  }
+
+  /* We really expect the cursor position to be set by now */
+  if(active && (new_cursor.row == -1 || new_cursor.col == -1)) {
+    fprintf(stderr, "screen_resize failed to update cursor position\n");
+    abort();
   }
 
   if(old_row >= 0 && bufidx == BUFIDX_PRIMARY) {
     /* Push spare lines to scrollback buffer */
-    int row;
-    for(row = 0; row <= old_row; row++)
+    for(int row = 0; row <= old_row; row++)
       sb_pushline_from_row(screen, row);
     if(active)
       statefields->pos.row -= (old_row + 1);
@@ -553,9 +685,8 @@ static void resize_buffer(VTermScreen *screen, int bufidx, int new_rows, int new
       for(pos.col = 0; pos.col < old_cols && pos.col < new_cols; pos.col += screen->sb_buffer[pos.col].width) {
         VTermScreenCell *src = &screen->sb_buffer[pos.col];
         ScreenCell *dst = &new_buffer[pos.row * new_cols + pos.col];