From effcc27f75408c276c2900429af96ce6f2ec9a6d Mon Sep 17 00:00:00 2001
From: Tangles <andyrthomson@gmail.com>
Date: Thu, 13 Feb 2020 23:27:01 +1100
Subject: [PATCH] userprefs - getpref() now calls dgl_format_str() on the
 'fallback' value

which is recursive. getpref() and dgl_format_str both now return a
dynamic string which must be freed.
---
 dgamelaunch.c | 15 +++++++++++----
 dgamelaunch.h |  2 +-
 dgl-common.c  |  6 +++++-
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/dgamelaunch.c b/dgamelaunch.c
index f3c83ce..94cf4b9 100644
--- a/dgamelaunch.c
+++ b/dgamelaunch.c
@@ -404,6 +404,7 @@ bannerstr_substprefs(char *buf, char *bufnew, int buflen)
     char *dst = bufnew;
     char *varname = NULL;
     char *fallback = NULL;
+    char *gpr = NULL;
     int isdollar = 0;
     if (!src) return NULL;
     while (*src && dst < bufnew + buflen - 1) {
@@ -423,7 +424,11 @@ bannerstr_substprefs(char *buf, char *bufnew, int buflen)
                 fallback = src + 1;
             } else if (*src == '}') {
                 *src = '\0';
-                snprintf(dst, bufnew + buflen - dst - 1, "%s", getpref(varname, fallback));
+                snprintf(dst, bufnew + buflen - dst - 1, "%s", gpr = getpref(varname, fallback));
+                if (gpr) {
+                    free(gpr); 
+                    gpr = NULL;
+                }
                 for (; *dst; dst++);
                 fallback = varname = NULL;
             }
@@ -2243,14 +2248,16 @@ writeprefs ()
     return prefcount;
 }
 
-const char *
+/* getpref allocates memory for the return value.
+   This must be freed when finished */
+char *
 getpref(char *key, char *fallback)
 {
     struct userpref *cpref;
     for (cpref = userprefs; cpref; cpref = cpref->npref)
         if (!strcmp(cpref->name, key))
-            return (const char *)cpref->value;
-    return fallback ? (const char *)fallback : "";
+            return strdup(cpref->value);
+    return fallback ? dgl_format_str(0, me, fallback, NULL) : strdup("");
 }
 
 int
diff --git a/dgamelaunch.h b/dgamelaunch.h
index b746074..a4695cb 100644
--- a/dgamelaunch.h
+++ b/dgamelaunch.h
@@ -361,7 +361,7 @@ extern void graceful_exit(int status);
 extern int purge_stale_locks(int game);
 extern int readprefs(void);
 extern int writeprefs(void);
-extern const char *getpref(char *key, char *fallback);
+extern char *getpref(char *key, char *fallback);
 extern int setpref(char *key, char *val);
 extern int askpref(char *prompt, char *key);
 /*extern int menuloop(void);*/
diff --git a/dgl-common.c b/dgl-common.c
index 426f9ce..868ade2 100644
--- a/dgl-common.c
+++ b/dgl-common.c
@@ -122,12 +122,15 @@ dgl_find_menu(char *menuname)
  * %N, %W, %L (char; first character of their lowercase counterparts)
  * ${varname[:default]} expands to userpref value of varname if defined, else
  * default if specified.
+ *
+ * Now returns a dynamically allocated string which must be freed.
  */
 char *
 dgl_format_str(int game, struct dg_user *me, char *str, char *plrname)
 {
     char buf[1024];
     char *f, *p, *end, *varname = NULL, *fallback = NULL;
+    char *gpr = NULL;
     int ispercent = 0;
     int isbackslash = 0;
     int isdollar = 0;
@@ -147,7 +150,8 @@ dgl_format_str(int game, struct dg_user *me, char *str, char *plrname)
            }
            if (*f == '}') {
                *f = '\0';
-               snprintf(p, end + 1 - p, "%s", getpref(varname, fallback));
+               snprintf(p, end + 1 - p, "%s", gpr = getpref(varname, fallback));
+               if (gpr) free(gpr);
                for (; *p; p++);
                varname = fallback = NULL;
            }
-- 
2.47.3