[glibc/release/2.34/master] intl: Avoid -Wuse-after-free [BZ #26779]

[Florian Weimer <fw@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=d36f457870a807f6f29880a2f2bde5e9b761f00c

commit d36f457870a807f6f29880a2f2bde5e9b761f00c
Author: Martin Sebor <msebor@redhat.com>
Date:   Tue Jan 25 17:38:31 2022 -0700

    intl: Avoid -Wuse-after-free [BZ #26779]
    
    Reviewed-by: Carlos O'Donell <carlos@redhat.com>
    (cherry picked from commit 7845064d2d5a50e347ee9f4b78ec5e6316190154)

Diff:
---
 intl/localealias.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/intl/localealias.c b/intl/localealias.c
index 375af2b031..28041f2a48 100644
--- a/intl/localealias.c
+++ b/intl/localealias.c
@@ -318,7 +318,15 @@ read_alias_file (const char *fname, int fname_len)
 
 		  if (string_space_act + alias_len + value_len > string_space_max)
 		    {
-		      /* Increase size of memory pool.  */
+#pragma GCC diagnostic push
+
+#if defined __GNUC__ && __GNUC__ >= 12
+  /* Suppress the valid GCC 12 warning until the code below is changed
+     to avoid using pointers to the reallocated block.  */
+#  pragma GCC diagnostic ignored "-Wuse-after-free"
+#endif
+
+		    /* Increase size of memory pool.  */
 		      size_t new_size = (string_space_max
 					 + (alias_len + value_len > 1024
 					    ? alias_len + value_len : 1024));
@@ -351,6 +359,8 @@ read_alias_file (const char *fname, int fname_len)
 					   value, value_len);
 		  string_space_act += value_len;
 
+#pragma GCC diagnostic pop
+
 		  ++nmap;
 		  ++added;
 		}