Merge pull request #130 from rouault/fix_129

SHPOpenLL(): avoid GDAL specific error message when .shx is missing

shpopen.c

@@ -46,6 +46,12 @@
 #endif
 #endif
 
+/* Allows customization of the message in vendored builds (such as GDAL) */
+#ifndef SHP_RESTORE_SHX_HINT_MESSAGE
+#define SHP_RESTORE_SHX_HINT_MESSAGE \
+ " Use SHPRestoreSHX() to restore or create it."
+#endif
+
 /************************************************************************/
 /* SHPWriteHeader() */
 /* */
@@ -324,14 +330,14 @@ SHPHandle SHPAPI_CALL SHPOpenLL(const char *pszLayer, const char *pszAccess,
 
  if (psSHP->fpSHX == SHPLIB_NULLPTR)
  {
- const size_t nMessageLen = strlen(pszFullname) * 2 + 256;
+ const size_t nMessageLen =
+ 64 + strlen(pszFullname) * 2 + strlen(SHP_RESTORE_SHX_HINT_MESSAGE);
  char *pszMessage = STATIC_CAST(char *, malloc(nMessageLen));
  pszFullname[nLenWithoutExtension] = 0;
- snprintf(pszMessage, nMessageLen,
- "Unable to open %s.shx or %s.SHX. "
- "Set SHAPE_RESTORE_SHX config option to YES to restore or "
- "create it.",
- pszFullname, pszFullname);
+ snprintf(
+ pszMessage, nMessageLen,
+ "Unable to open %s.shx or %s.SHX." SHP_RESTORE_SHX_HINT_MESSAGE,
+ pszFullname, pszFullname);
  psHooks->Error(pszMessage);
  free(pszMessage);