fix: Add tree-sitter dependency to CI and initialize line cap

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Install build tools
         run: |
           sudo apt-get update
-          sudo apt-get install -y meson ninja-build gcc
+          sudo apt-get install -y meson ninja-build gcc libtree-sitter-dev
 
       - name: Configure (release)
         run: meson setup build --buildtype=release

src/buffer.c

@@ -41,6 +41,7 @@ static void buffer_append_line(buffer_t *buf, const char *data, size_t len)
     buffer_ensure_line_cap(buf, buf->num_lines + 1);
     line_t *line = &buf->lines[buf->num_lines];
     line->chars = NULL;
+    line->cap = 0;
     line->len = 0;
     if (len > 0) {
         line_ensure_cap(line, len);