detectflash: preserve errors from lower layers for user to see

git-svn-id: https://urjtag.svn.sourceforge.net/svnroot/urjtag/trunk@1861 b68d4a1b-bc3d-0410-92ed-d4ac073336b7

urjtag/ChangeLog

@@ -3,6 +3,11 @@
   * src/flash/amd_flash.c (urj_flash_amd_detect): Move the bus address range
     checks up to before we actually attempt to read/write the bus.
 
+  * src/flash/detectflash.c (urj_flash_detectflash): Do not always clobber the
+    error value when we could not find a flash.  If the lower layer logged an
+    error, then we probably want the user to see that rather than a generic
+    "flash not found".
+
 2010-09-27  Mike Frysinger  <vapier@gentoo.org>
 
   * data/analog/bf533/bf533: Drop brackets from ADDR and DATA signals to match

urjtag/src/flash/detectflash.c

@@ -66,6 +66,8 @@ urj_flash_detectflash (urj_log_level_t ll, urj_bus_t *bus, uint32_t adr)
         return URJ_STATUS_FAIL;
     }
 
+    urj_error_reset ();
+
     urj_flash_cleanup();
 
     URJ_BUS_PREPARE (bus);
@@ -94,7 +96,9 @@ urj_flash_detectflash (urj_log_level_t ll, urj_bus_t *bus, uint32_t adr)
 
     if (urj_flash_cfi_array == NULL)
     {
-        urj_error_set (URJ_ERROR_NOTFOUND, _("Flash not found"));
+        /* Preserve error from lower layers if they set one */
+        if (urj_error_get () == URJ_ERROR_OK)
+            urj_error_set (URJ_ERROR_NOTFOUND, _("Flash not found"));
         return URJ_STATUS_FAIL;
     }