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/api/buffer.c

@@ -85,9 +85,9 @@ String buffer_get_line(Buffer buffer, Integer index, Error *err)
 /// @return False when updates couldn't be enabled because the buffer isn't
 ///         loaded; otherwise True.
 Boolean nvim_buf_attach(uint64_t channel_id,
-                                 Buffer buffer,
-                                 Boolean send_buffer,
-                                 Error *err)
+                        Buffer buffer,
+                        Boolean send_buffer,
+                        Error *err)
   FUNC_API_SINCE(4) FUNC_API_REMOTE_ONLY
 {
   buf_T *buf = find_buffer_by_handle(buffer, err);
@@ -106,8 +106,8 @@ Boolean nvim_buf_attach(uint64_t channel_id,
 /// @return False when updates couldn't be disabled because the buffer
 ///         isn't loaded; otherwise True.
 Boolean nvim_buf_detach(uint64_t channel_id,
-                                 Buffer buffer,
-                                 Error *err)
+                        Buffer buffer,
+                        Error *err)
   FUNC_API_SINCE(4) FUNC_API_REMOTE_ONLY
 {
   buf_T *buf = find_buffer_by_handle(buffer, err);

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,
-                             int64_t num_removed, bool send_tick)
+void buffer_updates_send_changes(buf_T *buf,
+                                 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;
-        linedata.items = xcalloc(sizeof(Object), num_added);
+        // True now, but a compile time reminder for future systems we support
+        // 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
-#define BUFFER_UPDATES_H
+#ifndef NVIM_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,
-                             int64_t num_removed, bool send_tick);
+void buffer_updates_send_changes(buf_T *buf,
+                                 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/ex_cmds.c

@@ -4022,7 +4022,7 @@ skip:
       int64_t num_added = last_line - first_line;
       int64_t num_removed = num_added - i;
       buffer_updates_send_changes(curbuf, first_line, num_added, num_removed,
-                              send_buffer_update_changedtick);
+                                  send_buffer_update_changedtick);
     }
   }
 

src/nvim/fold.c

@@ -754,7 +754,7 @@ deleteFold (
       // notification that includes every line that was part of the fold
       int64_t num_changed = last_lnum - first_lnum;
       buffer_updates_send_changes(curbuf, first_lnum, num_changed,
-                              num_changed, true);
+                                  num_changed, true);
     }
   }
 }
@@ -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
-    // anyway since it won't do any harm.
+    // u_save() is unable to save the buffer line, but we send the
+    // 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/misc1.c

@@ -1921,9 +1921,9 @@ changed_lines(
     linenr_T lnume,       // line below last changed line
     long xtra,            // number of extra lines (negative when deleting)
     bool send_update  // some callers like undo/redo call changed_lines()
-                          // and then increment b_changedtick *again*. This flag
-                          // allows these callers to send the nvim_buf_update events
-                          // after they're done modifying b_changedtick.
+                      // and then increment b_changedtick *again*. This flag
+                      // allows these callers to send the nvim_buf_update events
+                      // after they're done modifying b_changedtick.
 )
 {
   changed_lines_buf(curbuf, lnum, lnume, xtra);

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
-  // buffer contents
+  // don't send a nvim_buf_update for this undo is part of 'inccommand' playing
+  // with buffer contents
   u_doit(count, true, false);
 
   if (curbuf->b_u_curhead == NULL) {