provider: check #Call() if g:loaded_xx_provider=2

2 files changed, 19 insertions, 7 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index dc18532b40..d82a081c27 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -23996,8 +23996,7 @@ bool eval_has_provider(const char *name)
     if (get_var_tv(buf, len, &tv, NULL, false, true) == FAIL) {
       // Show a hint if Call() is defined but g:loaded_xx_provider is missing.
       snprintf(buf, sizeof(buf), "provider#%s#Call", name);
-      bool has_call = !!find_func((char_u *)buf);
-      if (has_call && p_lpl) {
+      if (!!find_func((char_u *)buf) && p_lpl) {
         emsgf("provider: %s: missing required variable g:loaded_%s_provider",
               name, name);
       }
@@ -24005,9 +24004,21 @@ bool eval_has_provider(const char *name)
     }
   }
 
-  return (tv.v_type == VAR_NUMBER)
+  bool ok = (tv.v_type == VAR_NUMBER)
     ? 2 == tv.vval.v_number  // Value of 2 means "loaded and working".
     : false;
+
+  if (ok) {
+    // Call() must be defined if provider claims to be working.
+    snprintf(buf, sizeof(buf), "provider#%s#Call", name);
+    if (!find_func((char_u *)buf)) {
+      emsgf("provider: %s: g:loaded_%s_provider=2 but %s is not defined",
+            name, name, buf);
+      ok = false;
+    }
+  }
+
+  return ok;
 }
 
 /// Writes "<sourcing_name>:<sourcing_lnum>" to `buf[bufsize]`.
diff --git a/test/functional/provider/provider_spec.lua b/test/functional/provider/provider_spec.lua
index 4220ec21cf..bfb0bbc3a3 100644
--- a/test/functional/provider/provider_spec.lua
+++ b/test/functional/provider/provider_spec.lua
@@ -1,6 +1,6 @@
 
 local helpers = require('test.functional.helpers')(after_each)
-local clear, eq, eval = helpers.clear, helpers.eq, helpers.eval
+local clear, eval = helpers.clear, helpers.eval
 local command = helpers.command
 local expect_err = helpers.expect_err
 
@@ -9,7 +9,7 @@ describe('providers', function()
     clear('--cmd', 'let &rtp = "test/functional/fixtures,".&rtp')
   end)
 
-  it('must define g:loaded_xx_provider', function()
+  it('with #Call(), missing g:loaded_xx_provider', function()
     command('set loadplugins')
     -- Using test-fixture with broken impl:
     -- test/functional/fixtures/autoload/provider/python.vim
@@ -17,9 +17,10 @@ describe('providers', function()
       eval, "has('python')")
   end)
 
-  it('without Call() but with g:loaded_xx_provider', function()
+  it('with g:loaded_xx_provider, missing #Call()', function()
     -- Using test-fixture with broken impl:
     -- test/functional/fixtures/autoload/provider/ruby.vim
-    eq(1, eval("has('ruby')"))
+    expect_err('Vim:provider: ruby: g:loaded_ruby_provider=2 but provider#ruby#Call is not defined',
+      eval, "has('ruby')")
   end)
 end)