lovr.filesystem.write/append returns success instead of size;

We don't have a good way of returning filesystem error messages yet,
but it's still useful to return a boolean instead of a number to
detect failure of zero byte writes.  Exposing the number of bytes
written is kind of weird since it's not very actionable.

src/api/l_filesystem.c

@@ -86,7 +86,8 @@ static int l_lovrFilesystemAppend(lua_State* L) {
   } else {
     return luax_typeerror(L, 2, "string or Blob");
   }
-  lua_pushinteger(L, lovrFilesystemWrite(path, data, size, true));
+  bool success = lovrFilesystemWrite(path, data, size, true);
+  lua_pushboolean(L, success);
   return 1;
 }
 
@@ -334,7 +335,8 @@ static int l_lovrFilesystemWrite(lua_State* L) {
   } else {
     return luax_typeerror(L, 2, "string or Blob");
   }
-  lua_pushinteger(L, lovrFilesystemWrite(path, data, size, false));
+  bool success = lovrFilesystemWrite(path, data, size, false);
+  lua_pushboolean(L, success);
   return 1;
 }
 

src/modules/filesystem/filesystem.c

@@ -376,20 +376,22 @@ bool lovrFilesystemRemove(const char* path) {
   return valid(path) && concat(resolved, state.savePath, state.savePathLength, path, strlen(path)) && fs_remove(resolved);
 }
 
-size_t lovrFilesystemWrite(const char* path, const char* content, size_t size, bool append) {
+bool lovrFilesystemWrite(const char* path, const char* content, size_t size, bool append) {
   char resolved[LOVR_PATH_MAX];
   if (!valid(path) || !concat(resolved, state.savePath, state.savePathLength, path, strlen(path))) {
-    return 0;
+    return false;
   }
 
   fs_handle file;
   if (!fs_open(resolved, append ? OPEN_APPEND : OPEN_WRITE, &file)) {
-    return 0;
+    return false;
   }
 
-  fs_write(file, content, &size);
-  fs_close(file);
-  return size;
+  if (!fs_write(file, content, &size)) {
+    return false;
+  }
+
+  return fs_close(file);
 }
 
 // Paths

src/modules/filesystem/filesystem.h

@@ -30,7 +30,7 @@ bool lovrFilesystemSetIdentity(const char* identity, bool precedence);
 const char* lovrFilesystemGetSaveDirectory(void);
 bool lovrFilesystemCreateDirectory(const char* path);
 bool lovrFilesystemRemove(const char* path);
-size_t lovrFilesystemWrite(const char* path, const char* content, size_t size, bool append);
+bool lovrFilesystemWrite(const char* path, const char* content, size_t size, bool append);
 size_t lovrFilesystemGetAppdataDirectory(char* buffer, size_t size);
 size_t lovrFilesystemGetExecutablePath(char* buffer, size_t size);
 size_t lovrFilesystemGetUserDirectory(char* buffer, size_t size);