From 24f845cdd8efd8f66d5ecbc82431a7029cfedea9 Mon Sep 17 00:00:00 2001
From: Stefan Rueger <stefan.rueger@urclocks.com>
Date: Thu, 1 Jun 2023 21:46:09 +0100
Subject: [PATCH] Guard pgm->page_erase() from being called when unset

---
 src/avr.c      | 2 +-
 src/avrcache.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/avr.c b/src/avr.c
index 15067cef..14e3076a 100644
--- a/src/avr.c
+++ b/src/avr.c
@@ -1054,7 +1054,7 @@ int avr_write_mem(const PROGRAMMER *pgm, const AVRPART *p, const AVRMEM *m, int
 
       if (need_write) {
         rc = 0;
-        if (auto_erase)
+        if (auto_erase && pgm->page_erase)
           rc = pgm->page_erase(pgm, p, cm, pageaddr);
         if (rc >= 0)
           rc = pgm->paged_write(pgm, p, cm, cm->page_size, pageaddr, cm->page_size);
diff --git a/src/avrcache.c b/src/avrcache.c
index da40c7a7..b0cb51da 100644
--- a/src/avrcache.c
+++ b/src/avrcache.c
@@ -549,7 +549,7 @@ int avr_flush_cache(const PROGRAMMER *pgm, const AVRPART *p) {
 
       for(int iwr = 0, pgno = 0, n = 0; n < cp->size; pgno++, n += cp->page_size) {
         if(cp->iscached[pgno] && memcmp(cp->copy + n, cp->cont + n, cp->page_size)) {
-          if(!chiperase && mems[i].pgerase)
+          if(!chiperase && mems[i].pgerase && pgm->page_erase)
             pgm->page_erase(pgm, p, mem, n);
           if(writeCachePage(cp, pgm, p, mem, n, 1) < 0)
             return LIBAVRDUDE_GENERAL_FAILURE;