Migrate the read limit into env_dispatch

src/env.cpp

@@ -58,11 +58,6 @@
 /// At init, we read all the environment variables from this array.
 extern char **environ;
 
-// Limit `read` to 10 MiB (bytes not wide chars) by default. This can be overridden by the
-// fish_read_limit variable.
-#define READ_BYTE_LIMIT 10 * 1024 * 1024
-size_t read_byte_limit = READ_BYTE_LIMIT;
-
 /// The character used to delimit path and non-path variables in exporting and in string expansion.
 static const wchar_t PATH_ARRAY_SEP = L':';
 static const wchar_t NONPATH_ARRAY_SEP = L' ';
@@ -349,20 +344,6 @@ void env_stack_t::set_pwd_from_getcwd() {
     set_one(L"PWD", ENV_EXPORT | ENV_GLOBAL, cwd);
 }
 
-/// Allow the user to override the limit on how much data the `read` command will process.
-/// This is primarily for testing but could be used by users in special situations.
-void env_stack_t::set_read_limit() {
-    auto read_byte_limit_var = this->get(L"fish_read_limit");
-    if (!read_byte_limit_var.missing_or_empty()) {
-        size_t limit = fish_wcstoull(read_byte_limit_var->as_string().c_str());
-        if (errno) {
-            debug(1, "Ignoring fish_read_limit since it is not valid");
-        } else {
-            read_byte_limit = limit;
-        }
-    }
-}
-
 void env_stack_t::mark_changed_exported() { vars_stack().mark_changed_exported(); }
 
 wcstring environment_t::get_pwd_slash() const {
@@ -537,7 +518,6 @@ void env_init(const struct config_paths_t *paths /* or NULL */) {
         vars.set_pwd_from_getcwd();
     }
     vars.set_termsize();    // initialize the terminal size variables
-    vars.set_read_limit();  // initialize the read_byte_limit
 
     // Set fish_bind_mode to "default".
     vars.set_one(FISH_BIND_MODE_VAR, ENV_GLOBAL, DEFAULT_BIND_MODE);

src/env.h

@@ -268,9 +268,6 @@ class env_stack_t final : public environment_t {
     /// Sets up argv as the given null terminated array of strings.
     void set_argv(const wchar_t *const *argv);
 
-    /// Update the read_byte_limit variable.
-    void set_read_limit();
-
     /// Mark that exported variables have changed.
     void mark_changed_exported();
 

src/env_dispatch.cpp

@@ -247,8 +247,6 @@ static void handle_term_size_change(env_stack_t &vars) {
     invalidate_termsize(true);  // force fish to update its idea of the terminal size plus vars
 }
 
-static void handle_read_limit_change(env_stack_t &vars) { vars.set_read_limit(); }
-
 static void handle_fish_history_change(env_stack_t &vars) {
     reader_change_history(history_session_id(vars));
 }
@@ -289,6 +287,20 @@ static void handle_fish_use_posix_spawn_change(const environment_t &vars) {
         use_posix_spawn.missing_or_empty() ? true : bool_from_string(use_posix_spawn->as_string());
 }
 
+/// Allow the user to override the limit on how much data the `read` command will process.
+/// This is primarily for testing but could be used by users in special situations.
+static void handle_read_limit_change(const environment_t &vars) {
+    auto read_byte_limit_var = vars.get(L"fish_read_limit");
+    if (!read_byte_limit_var.missing_or_empty()) {
+        size_t limit = fish_wcstoull(read_byte_limit_var->as_string().c_str());
+        if (errno) {
+            debug(1, "Ignoring fish_read_limit since it is not valid");
+        } else {
+            read_byte_limit = limit;
+        }
+    }
+}
+
 /// Populate the dispatch table used by `env_dispatch_var_change()` to efficiently call the
 /// appropriate function to handle a change to a variable.
 /// Note this returns a new-allocated value that we expect to leak.
@@ -326,6 +338,7 @@ static void run_inits(const environment_t &vars) {
     init_curses(vars);
     guess_emoji_width(vars);
     update_wait_on_escape_ms(vars);
+    handle_read_limit_change(vars);
 }
 
 /// Updates our idea of whether we support term256 and term24bit (see issue #10222).
@@ -524,3 +537,7 @@ bool term_supports_setting_title() { return can_set_term_title; }
 
 /// Miscellaneous variables.
 bool g_use_posix_spawn = false;
+
+// Limit `read` to 10 MiB (bytes not wide chars) by default. This can be overridden by the
+// fish_read_limit variable.
+size_t read_byte_limit = 10 * 1024 * 1024;