feat: has('terminfo')

Problem:
No way to detect at runtime if the build includes unibilium (or whatever
terminfo layer we swap it with later).

Solution:
Support `has('terminfo')`.

.github/workflows/build.yml

@@ -55,7 +55,7 @@ jobs:
         run: make install
 
   use-existing-src:
-    name: Test USE_EXISTING_SRC_DIR=ON builds with no network access
+    name: Test offline build (USE_EXISTING_SRC_DIR=ON builds with no network access)
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6

.github/workflows/test.yml

@@ -176,7 +176,7 @@ jobs:
       - name: Install
         run: |
           cmake --install build
-          "$INSTALL_PREFIX/bin/nvim" --version
+          "$INSTALL_PREFIX/bin/nvim" -V1 --version
           if ! "$INSTALL_PREFIX/bin/nvim" -u NONE -e -c ':help' -c ':qall'; then
             echo "Running ':help' in the installed nvim failed."
             echo "Maybe the helptags have not been generated properly."

BUILD.md

@@ -300,6 +300,8 @@ custom terminfo at runtime, use
 make CMAKE_EXTRA_FLAGS="-DENABLE_UNIBILIUM=0" DEPS_CMAKE_FLAGS="-DUSE_BUNDLED_UNIBILIUM=0"
 ```
 
+To confirm at runtime that unibilium was not included, check `has('terminfo') == 1`.
+
 ### How to build static binary (on Linux)
 
 1. Use a linux distribution which uses musl C. We will use Alpine Linux but any distro with musl should work. (glibc does not support static linking)

src/nvim/eval/funcs.c

@@ -2757,6 +2757,9 @@ static void f_has(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     "tablineat",
     "tag_binary",
     "termguicolors",
+#ifdef HAVE_UNIBILIUM
+    "terminfo",
+#endif
     "termresponse",
     "textobjects",
     "timers",

test/functional/vimscript/has_spec.lua

@@ -64,6 +64,17 @@ describe('has()', function()
     end
   end)
 
+  it('"terminfo"', function()
+    -- Looks like "HAVE_UNIBILIUM ", "HAVE_UNIBILIUM=1", "HAVE_UNIBILIUM off", ….
+    -- Capture group returns the "1"/"off"/….
+    local build_flag =
+      vim.trim((n.exec_capture('verbose version'):match('HAVE_UNIBILIUM([^-]+)') or ''):lower())
+    -- XXX: the match() above fails in CI so currently we assume CI always builds with unibilium.
+    local is_enabled = t.is_ci()
+      or not (build_flag == '' or build_flag == 'false' or build_flag == '0' or build_flag == 'off')
+    eq(is_enabled and 1 or 0, fn.has('terminfo'))
+  end)
+
   it('"wsl"', function()
     local is_wsl = vim.uv.os_uname()['release']:lower():match('microsoft') and true or false
     if is_wsl then