Add tilde expansion for the open file dialog

sysmisc.c

@@ -5,6 +5,30 @@
 #include <errno.h>
 #include <sys/stat.h>
 
+static char const *const xdg_config_home_env = "XDG_CONFIG_HOME";
+static char const *const home_env = "HOME";
+
+void expand_home_tilde(oso **path) {
+  oso *s = *path;
+  size_t n = osolen(s);
+  if (n < 2)
+    return;
+  if (osoc(s)[0] != '~' || osoc(s)[1] != '/')
+    return;
+  char const *homedir = getenv(home_env);
+  if (!homedir)
+    return;
+  size_t hlen = strlen(homedir);
+  osoensurecap(&s, n + hlen - 1);
+  if (!s)
+    goto done;
+  memmove((char *)s + hlen, (char *)s + 1, n); // includes '\0'
+  memcpy((char *)s, homedir, hlen);
+  osopokelen(s, n + hlen - 1);
+done:
+  *path = s;
+}
+
 ORCA_NOINLINE
 Cboard_error cboard_copy(Glyph const *gbuffer, Usz field_height,
                          Usz field_width, Usz rect_y, Usz rect_x, Usz rect_h,
@@ -220,9 +244,6 @@ typedef enum {
   Conf_dir_no_home,
 } Conf_dir_error;
 
-static char const *const xdg_config_home_env = "XDG_CONFIG_HOME";
-static char const *const home_env = "HOME";
-
 static Conf_dir_error try_get_conf_dir(oso **out) {
   char const *xdgcfgdir = getenv(xdg_config_home_env);
   if (xdgcfgdir) {

sysmisc.h

@@ -1,6 +1,9 @@
 #pragma once
 #include "base.h"
 #include <stdio.h> // FILE cannot be forward declared
+struct oso;
+
+void expand_home_tilde(struct oso **path);
 
 typedef enum {
   Cboard_error_none = 0,
@@ -127,7 +130,7 @@ typedef struct {
   uint32_t stateflags;
 } Ezconf_w;
 
-void ezconf_w_start(Ezconf_w *ezcw, Ezconf_opt *optsbuffer,
+void ezconf_w_start(Ezconf_w *ezcw, Ezconf_opt *optsbuffer, size_t buffercap,
-                    size_t buffercap, char const *conf_file_name);
+                    char const *conf_file_name);
 void ezconf_w_addopt(Ezconf_w *ezcw, char const *key, intptr_t id);
 bool ezconf_w_step(Ezconf_w *ezcw);

tui_main.c

@@ -3139,6 +3139,9 @@ staticni Tui_menus_result tui_drive_menus(Tui *t, int key) {
         switch (qform_id(qf)) {
         case Open_form_id: {
           oso *temp_name = get_nonempty_singular_form_text(qf);
+          if (!temp_name)
+            break;
+          expand_home_tilde(&temp_name);
           if (!temp_name)
             break;
           bool added_hist = undo_history_push(&t->ged.undo_hist, &t->ged.field,