Add a regression test for troydhanson#241.

tests/Makefile

@@ -12,7 +12,7 @@ PROGS = test1 test2 test3 test4 test5 test6 test7 test8 test9   \
         test66 test67 test68 test69 test70 test71 test72 test73 \
         test74 test75 test76 test77 test78 test79 test80 test81 \
         test82 test83 test84 test85 test86 test87 test88 test89 \
-        test90 test91 test92 test93 test94 test95 test96
+        test90 test91 test92 test93 test94 test95 test96 test97
 CFLAGS += -I$(HASHDIR)
 #CFLAGS += -DHASH_BLOOM=16
 #CFLAGS += -O2

tests/README

@@ -98,6 +98,7 @@ test93: alt_fatal
 test94: utlist with fields named other than 'next' and 'prev'
 test95: utstack
 test96: HASH_FUNCTION + HASH_KEYCMP
+test97: DL_SORT static-analysis false positive (#241)
 
 Other Make targets
 ================================================================================

tests/test32.c

@@ -32,7 +32,6 @@ int main()
         strcpy(name->bname, linebuf);
         DL_PREPEND(head, name);
     }
-    /* DL_SORT(head, namecmp); */
     DL_FOREACH(head,tmp) {
         printf("%s", tmp->bname);
     }

tests/test34.c

@@ -32,7 +32,6 @@ int main()
         strcpy(name->bname, linebuf);
         CDL_PREPEND(head, name);
     }
-    /* CDL_SORT(head, namecmp); */
     CDL_FOREACH(head,tmp) {
         printf("%s", tmp->bname);
     }

tests/test97.c

@@ -0,0 +1,54 @@
+#include "utlist.h"
+#include <assert.h>
+#include <stdlib.h>
+
+struct item {
+    int x;
+    struct item *prev;
+    struct item *next;
+};
+
+static int sort_cmp(void *a, void *b)
+{
+    struct item *item1 = (struct item *)a;
+    struct item *item2 = (struct item *)b;
+    return item1->x - item2->x;
+}
+
+void sort_them(struct item **items)
+{
+    DL_SORT(*items, sort_cmp);
+}
+
+int main()
+{
+    struct item *list = NULL;
+    struct item a = { 2, NULL, NULL };
+    struct item b = { 1, NULL, NULL };
+    sort_them(&list);
+    assert(list == NULL);
+
+    DL_APPEND(list, &a);
+    assert(list == &a);
+    assert(a.prev == &a);
+    assert(a.next == NULL);
+    sort_them(&list);
+    assert(list == &a);
+    assert(a.prev == &a);
+    assert(a.next == NULL);
+
+    DL_APPEND(list, &b);
+    assert(list == &a);
+    assert(a.prev == &b);
+    assert(a.next == &b);
+    assert(b.prev == &a);
+    assert(b.next == NULL);
+    sort_them(&list);
+    assert(list == &b);
+    assert(b.prev == &a);
+    assert(b.next == &a);
+    assert(a.prev == &b);
+    assert(a.next == NULL);
+
+    return 0;
+}