Fix crash in expansions

[exim.git] / src / src / expand.c

diff --git a/src/src/expand.c b/src/src/expand.c
index 2949579c5ac3192bcd4a60ffe6100dcb2c2edbc1..a7e6e4fb3ea7dbeb1893af97b1080d0c62177e9d 100644 (file)
--- a/src/src/expand.c
+++ b/src/src/expand.c
@@ -4733,6 +4733,7 @@ while (*s)
     reset in the middle of the buffer will make it inaccessible. */
 
     len = Ustrlen(value);
+    DEBUG(D_expand) debug_expansion_interim(US"value", value, len, !!(flags & ESI_SKIPPING));
     if (!yield && newsize != 0)
       {
       yield = g;
@@ -4746,12 +4747,15 @@ while (*s)
     continue;
     }
 
-  if (isdigit(*s))
+  if (isdigit(*s))             /* A $<n> variable */
     {
     int n;
     s = read_cnumber(&n, s);
     if (n >= 0 && n <= expand_nmax)
+      {
+      DEBUG(D_expand) debug_expansion_interim(US"value", expand_nstring[n], expand_nlength[n], !!(flags & ESI_SKIPPING));
       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
+      }
     continue;
     }
 
@@ -4776,7 +4780,10 @@ while (*s)
       goto EXPAND_FAILED;
       }
     if (n >= 0 && n <= expand_nmax)
+      {
+      DEBUG(D_expand) debug_expansion_interim(US"value", expand_nstring[n], expand_nlength[n], !!(flags & ESI_SKIPPING));
       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
+      }
     continue;
     }
 
@@ -7158,6 +7165,7 @@ NOT_ITEM: ;
 
     /* Deal specially with operators that might take a certificate variable
     as we do not want to do the usual expansion. For most, expand the string.*/
+
     switch(c)
       {
 #ifndef DISABLE_TLS
@@ -7206,7 +7214,7 @@ NOT_ITEM: ;
     to the main loop top. */
 
      {
-     int start = yield->ptr;
+     unsigned expansion_start = gstring_length(yield);
      switch(c)
       {
       case EOP_BASE32:
@@ -8268,8 +8276,8 @@ NOT_ITEM: ;
 
        DEBUG(D_expand)
        {
-       const uschar * s = yield->s + start;
-       int i = yield->ptr - start;
+       const uschar * s = yield->s + expansion_start;
+       int i = gstring_length(yield) - expansion_start;
        BOOL tainted = is_tainted(s);
 
        DEBUG(D_noutf8)