Merge branch '674-abort-when-memory-allocation-fails' into 'master'

Resolve "abort when memory allocation fails"

Closes #674

See merge request isc-projects/bind9!1025

CHANGES

@@ -1,3 +1,5 @@
+5098.	[func]		Failed memory allocations are now fatal. [GL #674]
+
 5097.	[cleanup]	Remove embedded ATF unit testing framework
 			from BIND source distribution.  [GL !875]
 

bin/dnssec/dnssec-signzone.c

@@ -533,8 +533,6 @@ signset(dns_diff_t *del, dns_diff_t *add, dns_dbnode_t *node, dns_name_t *name,
 		arraysize += dns_rdataset_count(&sigset);
 	wassignedby = isc_mem_get(mctx, arraysize * sizeof(bool));
 	nowsignedby = isc_mem_get(mctx, arraysize * sizeof(bool));
-	if (wassignedby == NULL || nowsignedby == NULL)
-		fatal("out of memory");
 
 	for (i = 0; i < arraysize; i++)
 		wassignedby[i] = nowsignedby[i] = false;

lib/isc/mem.c

@@ -14,6 +14,7 @@
 #include <config.h>
 
 #include <inttypes.h>
+#include <errno.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -712,10 +713,32 @@ mem_putstats(isc__mem_t *ctx, void *ptr, size_t size) {
 
 static void *
 default_memalloc(void *arg, size_t size) {
+	void *ptr;
 	UNUSED(arg);
-	if (size == 0U)
-		size = 1;
-	return (malloc(size));
+
+	ptr = malloc(size);
+
+	/*
+	 * If the space cannot be allocated, a null pointer is returned. If the
+	 * size of the space requested is zero, the behavior is
+	 * implementation-defined: either a null pointer is returned, or the
+	 * behavior is as if the size were some nonzero value, except that the
+	 * returned pointer shall not be used to access an object.
+	 * [ISO9899 § 7.22.3]
+	 *
+	 * [ISO9899]
+	 *   ISO/IEC WG 9899:2011: Programming languages - C.
+	 *   International Organization for Standardization, Geneva, Switzerland.
+	 *   http://www.open-std.org/JTC1/SC22/WG14/www/docs/n1570.pdf
+	 */
+
+	if (ptr == NULL && size != 0) {
+		char strbuf[ISC_STRERRORSIZE];
+		strerror_r(errno, strbuf, sizeof(strbuf));
+		isc_error_fatal(__FILE__, __LINE__, "malloc failed: %s", strbuf);
+	}
+
+	return (ptr);
 }
 
 static void