[PATCH] libiberty: Always return NULL if d_add_substitution fails.

[Mark Wielaard]

d_add_substitution can fail for various reasons, like when the subs array
is full. If d_add_substitution fails d_substitution should return NULL
early and not try to continue. Every other call of d_add_substitution
is handled in the same way.

libiberty/ChangeLog:

        * cp-demangle.c (d_substitution): Return NULL if d_add_substitution
        fails.

diff --git a/libiberty/cp-demangle.c b/libiberty/cp-demangle.c
index 2c7d5c5..aeff7a7 100644
--- a/libiberty/cp-demangle.c
+++ b/libiberty/cp-demangle.c
@@ -3891,7 +3891,8 @@ d_substitution (struct d_info *di, int prefix)
                  /* If there are ABI tags on the abbreviation, it becomes
                     a substitution candidate.  */
                  dc = d_abi_tags (di, dc);
-                 d_add_substitution (di, dc);
+                 if (! d_add_substitution (di, dc))
+                   return NULL;
                }
              return dc;
            }