fix(lua): relax vim.wait() timeout validation #36900

Problem:
After bc0635a9fc `vim.wait()` rejects floats
and NaN values.

Solution:
Restore the prior behavior, while still supporting `math.huge`. Update
tests to cover float case.

runtime/doc/lua.txt

@@ -862,8 +862,8 @@ vim.wait({time}, {callback}, {interval}, {fast_only})             *vim.wait()*
         -- Wait up to 1000 ms or until `vim.g.foo` is true, at intervals of ~500 ms.
         vim.wait(1000, function() return vim.g.foo end, 500)
 
-        -- Wait up to 100 ms or until `vim.g.foo` is true, and get the callback results.
-        local ok, rv1, rv2, rv3 = vim.wait(100, function()
+        -- Wait indefinitely until `vim.g.foo` is true, and get the callback results.
+        local ok, rv1, rv2, rv3 = vim.wait(math.huge, function()
           return vim.g.foo, 'a', 42, { ok = { 'yes' } }
         end)
 
@@ -876,7 +876,8 @@ vim.wait({time}, {callback}, {interval}, {fast_only})             *vim.wait()*
 <
 
     Parameters: ~
-      • {time}       (`integer`) Number of milliseconds to wait
+      • {time}       (`number`) Number of milliseconds to wait. Must be
+                     non-negative number, any fractional part is truncated.
       • {callback}   (`fun(): boolean, ...?`) Optional callback. Waits until
                      {callback} returns true
       • {interval}   (`integer?`) (Approximate) number of milliseconds to wait

runtime/lua/vim/_meta/builtin.lua

@@ -195,8 +195,8 @@ function vim.schedule(fn) end
 --- -- Wait up to 1000 ms or until `vim.g.foo` is true, at intervals of ~500 ms.
 --- vim.wait(1000, function() return vim.g.foo end, 500)
 ---
---- -- Wait up to 100 ms or until `vim.g.foo` is true, and get the callback results.
---- local ok, rv1, rv2, rv3 = vim.wait(100, function()
+--- -- Wait indefinitely until `vim.g.foo` is true, and get the callback results.
+--- local ok, rv1, rv2, rv3 = vim.wait(math.huge, function()
 ---   return vim.g.foo, 'a', 42, { ok = { 'yes' } }
 --- end)
 ---
@@ -208,7 +208,8 @@ function vim.schedule(fn) end
 --- end
 --- ```
 ---
---- @param time integer Number of milliseconds to wait
+--- @param time number Number of milliseconds to wait. Must be non-negative number, any fractional
+--- part is truncated.
 --- @param callback? fun(): boolean, ... Optional callback. Waits until {callback} returns true
 --- @param interval? integer (Approximate) number of milliseconds to wait between polls
 --- @param fast_only? boolean If true, only |api-fast| events will be processed.

src/nvim/lua/executor.c

@@ -456,15 +456,9 @@ static int nlua_wait(lua_State *lstate)
   if (timeout_number < 0) {
     return luaL_error(lstate, "timeout must be >= 0");
   }
-  int64_t timeout;
-  if (isinf(timeout_number) || timeout_number > (double)INT64_MAX) {
-    timeout = INT64_MAX;
-  } else {
-    if (isnan(timeout_number) || timeout_number != trunc(timeout_number)) {
-      return luaL_error(lstate, "timeout has no integer representation");
-    }
-    timeout = (int64_t)timeout_number;
-  }
+  int64_t timeout = (isnan(timeout_number) || timeout_number > (double)INT64_MAX)
+                    ? INT64_MAX
+                    : (int64_t)timeout_number;
 
   int lua_top = lua_gettop(lstate);
 

test/functional/lua/vim_spec.lua

@@ -2319,7 +2319,7 @@ stack traceback:
         true,
         exec_lua [[
         local start_time = vim.uv.hrtime()
-        vim.wait(50, nil) -- select('#', ...) == 1
+        vim.wait(50.1, nil) -- select('#', ...) == 1
         return vim.uv.hrtime() - start_time > 25000
       ]]
       )