5 files changed, 11 insertions, 6 deletions
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index 99a41f4f6f..60535b13b3 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -2954,6 +2954,7 @@ void nvim_set_decoration_provider(Integer ns_id, DictionaryOf(LuaRef) opts,
   FUNC_API_SINCE(7) FUNC_API_LUA_ONLY
 {
   DecorProvider *p = get_decor_provider((NS)ns_id, true);
+  assert(p != NULL);
   decor_provider_clear(p);
 
   // regardless of what happens, it seems good idea to redraw
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index a75cc78b7e..a3fa9c986f 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -7200,9 +7200,13 @@ bool callback_from_typval(Callback *const callback, typval_T *const arg)
     r = FAIL;
   } else if (arg->v_type == VAR_FUNC || arg->v_type == VAR_STRING) {
     char_u *name = arg->vval.v_string;
-    func_ref(name);
-    callback->data.funcref = vim_strsave(name);
-    callback->type = kCallbackFuncref;
+    if (name != NULL) {
+      func_ref(name);
+      callback->data.funcref = vim_strsave(name);
+      callback->type = kCallbackFuncref;
+    } else {
+      r = FAIL;
+    }
   } else if (nlua_is_table_from_lua(arg)) {
     char_u *name = nlua_register_table_as_callable(arg);
 
diff --git a/src/nvim/ex_cmds2.c b/src/nvim/ex_cmds2.c
index 0a2802397d..56a14887df 100644
--- a/src/nvim/ex_cmds2.c
+++ b/src/nvim/ex_cmds2.c
@@ -2958,7 +2958,7 @@ int do_source(char_u *fname, int check_other, int is_vimrc)
   }
 
   if (l_do_profiling == PROF_YES) {
-    bool forceit;
+    bool forceit = false;
 
     // Check if we do profiling for this script.
     if (!si->sn_prof_on && has_profiling(true, si->sn_name, &forceit)) {
diff --git a/src/nvim/ex_session.c b/src/nvim/ex_session.c
index c1e52d6994..481febd16b 100644
--- a/src/nvim/ex_session.c
+++ b/src/nvim/ex_session.c
@@ -725,7 +725,7 @@ static int makeopens(FILE *fd, char_u *dirnow)
       }
     }
 
-    if (tab_firstwin->w_next != NULL) {
+    if (tab_firstwin != NULL && tab_firstwin->w_next != NULL) {
       // Go to the first window.
       PUTLINE_FAIL("wincmd t");
 
diff --git a/src/nvim/marktree.c b/src/nvim/marktree.c
index b3afdefac1..34acf64d83 100644
--- a/src/nvim/marktree.c
+++ b/src/nvim/marktree.c
@@ -849,7 +849,7 @@ bool marktree_splice(MarkTree *b,
   MarkTreeIter itr[1] = { 0 };
   MarkTreeIter enditr[1] = { 0 };
 
-  mtpos_t oldbase[MT_MAX_DEPTH];
+  mtpos_t oldbase[MT_MAX_DEPTH] = { 0 };
 
   marktree_itr_get_ext(b, start, itr, false, true, oldbase);
   if (!itr->node) {