From b1f8dd75d684b3dd00f147a63ef687a6b566fc7f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Wed, 10 Jul 2019 18:47:32 +0200
Subject: [PATCH] cell: we only need 4 bytes for the longest utf8 sequence

We don't *have* to NULL-terminate the utf8 string. So don't. This
makes the cell glyph 4 bytes exactly, which is better for alignment
and cache usage.
---
 render.c   | 2 +-
 terminal.h | 2 +-
 vt.c       | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/render.c b/render.c
index 65e2ab96..894bc939 100644
--- a/render.c
+++ b/render.c
@@ -101,7 +101,7 @@ render_cell(struct terminal *term, struct buffer *buf, const struct cell *cell,
 
     cairo_status_t status = cairo_scaled_font_text_to_glyphs(
         attrs_to_font(term, &cell->attrs), x, y + term->fextents.ascent,
-        cell->c, strlen(cell->c), &gseq.g, &new_glyphs,
+        cell->c, strnlen(cell->c, 4), &gseq.g, &new_glyphs,
         NULL, NULL, NULL);
 
     if (status != CAIRO_STATUS_SUCCESS)
diff --git a/terminal.h b/terminal.h
index 66cfebe0..16e53f22 100644
--- a/terminal.h
+++ b/terminal.h
@@ -68,7 +68,7 @@ struct attributes {
 
 struct cell {
     struct attributes attrs;
-    char c[5];
+    char c[4];
 } __attribute__((packed));
 
 struct scroll_region {
diff --git a/vt.c b/vt.c
index 8314c060..5d4127c5 100644
--- a/vt.c
+++ b/vt.c
@@ -757,7 +757,7 @@ action_print(struct terminal *term, uint8_t c)
     if (unlikely(term->charset[term->selected_charset] == CHARSET_GRAPHIC) &&
         c >= 0x41 && c <= 0x7e)
     {
-        strcpy(cell->c, vt100_0[c - 0x41]);
+        strncpy(cell->c, vt100_0[c - 0x41], sizeof(cell->c));
     } else {
         //LOG_DBG("print: ASCII: %c", c);
         cell->c[0] = c;