Enable -Wconversion

src/nvim/CMakeLists.txt

@@ -142,7 +142,6 @@ set(CONV_SOURCES
   message.c
   regexp.c
   screen.c
-  buffer_updates.c
   search.c
   spell.c
   spellfile.c

src/nvim/buffer_updates.c

@@ -2,6 +2,7 @@
 #include "nvim/memline.h"
 #include "nvim/api/private/helpers.h"
 #include "nvim/msgpack_rpc/channel.h"
+#include "nvim/assert.h"
 
 // Register a channel. Return True if the channel was added, or already added.
 // Return False if the channel couldn't be added because the buffer is
@@ -30,7 +31,10 @@ bool buffer_updates_register(buf_T *buf, uint64_t channel_id, bool send_buffer)
   Array linedata = ARRAY_DICT_INIT;
   if (send_buffer) {
     // collect buffer contents
-    size_t line_count = buf->b_ml.ml_line_count;
+    // True now, but a compile time reminder for future systems we support
+    STATIC_ASSERT(SIZE_MAX >= MAXLNUM, "size_t to small to hold the number of"
+                  " lines in a buffer");
+    size_t line_count = (size_t)buf->b_ml.ml_line_count;
     linedata.size = line_count;
     linedata.items = xcalloc(sizeof(Object), line_count);
     for (size_t i = 0; i < line_count; i++) {
@@ -118,8 +122,11 @@ void buffer_updates_unregister_all(buf_T *buf)
   }
 }
 
-void buffer_updates_send_changes(buf_T *buf, linenr_T firstline, int64_t num_added,
+void buffer_updates_send_changes(buf_T *buf,
-                             int64_t num_removed, bool send_tick)
+                                 linenr_T firstline,
+                                 int64_t num_added,
+                                 int64_t num_removed,
+                                 bool send_tick)
 {
   // if one the channels doesn't work, put its ID here so we can remove it later
   uint64_t badchannelid = 0;
@@ -148,8 +155,13 @@ void buffer_updates_send_changes(buf_T *buf, linenr_T firstline, int64_t num_add
     // linedata of lines being swapped in
     Array linedata = ARRAY_DICT_INIT;
     if (num_added > 0) {
-        linedata.size = num_added;
+        // True now, but a compile time reminder for future systems we support
-        linedata.items = xcalloc(sizeof(Object), num_added);
+        // Note that `num_added` is a `int64_t`, but still must be lower than
+        // `MAX_LNUM`
+        STATIC_ASSERT(SIZE_MAX >= MAXLNUM, "size_t to small to hold the number "
+                      "of lines in a buffer");
+        linedata.size = (size_t)num_added;
+        linedata.items = xcalloc(sizeof(Object), (size_t)num_added);
         for (int64_t i = 0; i < num_added; i++) {
           int64_t lnum = firstline + i;
           const char *bufstr = (char *)ml_get_buf(buf, (linenr_T)lnum, false);

src/nvim/buffer_updates.h

@@ -1,13 +1,16 @@
-#ifndef BUFFER_UPDATES_H
+#ifndef NVIM_BUFFER_UPDATES_H
-#define BUFFER_UPDATES_H
+#define NVIM_BUFFER_UPDATES_H
 
 #include "nvim/buffer_defs.h"
 
 bool buffer_updates_register(buf_T *buf, uint64_t channel_id, bool send_buffer);
 void buffer_updates_unregister(buf_T *buf, uint64_t channel_id);
 void buffer_updates_unregister_all(buf_T *buf);
-void buffer_updates_send_changes(buf_T *buf, linenr_T firstline, int64_t num_added,
+void buffer_updates_send_changes(buf_T *buf,
-                             int64_t num_removed, bool send_tick);
+                                 linenr_T firstline,
+                                 int64_t num_added,
+                                 int64_t num_removed,
+                                 bool send_tick);
 void buffer_updates_send_tick(buf_T *buf);
 
 #endif  // NVIM_BUFFER_UPDATES_H

src/nvim/fold.c

@@ -1607,8 +1607,8 @@ static void foldCreateMarkers(linenr_T start, linenr_T end)
 
   if (kv_size(curbuf->update_channels)) {
     // Note: foldAddMarker() may not actually change start and/or end if
-    // u_save() is unable to save the buffer line, but we send the nvim_buf_update
+    // u_save() is unable to save the buffer line, but we send the
-    // anyway since it won't do any harm.
+    // nvim_buf_update anyway since it won't do any harm.
     int64_t num_changed = 1 + end - start;
     buffer_updates_send_changes(curbuf, start, num_changed, num_changed, true);
   }

src/nvim/undo.c

@@ -1698,8 +1698,8 @@ bool u_undo_and_forget(int count)
     count = 1;
   }
   undo_undoes = true;
-  // don't send a nvim_buf_update for this undo is part of 'inccommand' playing with
+  // don't send a nvim_buf_update for this undo is part of 'inccommand' playing
-  // buffer contents
+  // with buffer contents
   u_doit(count, true, false);
 
   if (curbuf->b_u_curhead == NULL) {