tests: pacify gcc -fanalyzer on zerosize_ptr

* tests/test-memcasecmp.c (main):
* tests/test-memchr.c (main):
* tests/test-memchr2.c (main):
* tests/test-memcmp.c (main):
* tests/test-memmem.c (main):
* tests/test-memrchr.c (main):
* tests/unistr/test-chr.h (main):
* tests/unistr/test-cmp.h (test_cmp):
Check whether zerosize_ptr returns NULL before using it.
This pacifies GCC 10.1’s new fanalyzer option, and matches
other uses of zerosize_ptr.

2 files changed, 7 insertions, 2 deletions

diff --git a/tests/unistr/test-chr.h b/tests/unistr/test-chr.h
index b67be48861..f60610f22b 100644
--- a/tests/unistr/test-chr.h
+++ b/tests/unistr/test-chr.h
@@ -48,7 +48,9 @@ main (void)
   ASSERT (U_CHR (input, length, 'a') == input);
 
   ASSERT (U_CHR (input, 0, 'a') == NULL);
-  ASSERT (U_CHR (zerosize_ptr (), 0, 'a') == NULL);
+  void *page_boundary = zerosize_ptr ();
+  if (page_boundary)
+    ASSERT (U_CHR (page_boundary, 0, 'a') == NULL);
 
   ASSERT (U_CHR (input, length, 'b') == input + 1);
   ASSERT (U_CHR (input, length, 'c') == input + 2);
diff --git a/tests/unistr/test-cmp.h b/tests/unistr/test-cmp.h
index 38a5223f7a..207c59a775 100644
--- a/tests/unistr/test-cmp.h
+++ b/tests/unistr/test-cmp.h
@@ -20,7 +20,10 @@ static void
 test_cmp (void)
 {
   /* Test equal / not equal distinction.  */
-  ASSERT (U_CMP (zerosize_ptr (), zerosize_ptr (), 0) == 0);
+  void *page_boundary1 = zerosize_ptr ();
+  void *page_boundary2 = zerosize_ptr ();
+  if (page_boundary1 && page_boundary2)
+    ASSERT (U_CMP (page_boundary1, page_boundary2, 0) == 0);
   {
     static const UNIT input1[] = { 'f', 'o', 'o', 0 };
     static const UNIT input2[] = { 'f', 'o', 'o', 'b', 'a', 'r', 0 };