[gcc r11-9276] libstdc++: Fix out-of-bound array accesses in testsuite

[Jonathan Wakely]

https://gcc.gnu.org/g:092cc2c68a980554e239482bec4765fa64496d4b

commit r11-9276-g092cc2c68a980554e239482bec4765fa64496d4b
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Jul 21 20:38:51 2016 +0100

    libstdc++: Fix out-of-bound array accesses in testsuite
    
    I fixed some undefined behaviour in string tests in r238609, but I only
    fixed the narrow char versions. This applies the same fixes to the
    wchar_t ones. These problems were found when testing a patch to make
    std::basic_string usable in constexpr.
    
    libstdc++-v3/ChangeLog:
    
            * testsuite/21_strings/basic_string/modifiers/append/wchar_t/1.cc:
            Fix reads past the end of strings.
            * testsuite/21_strings/basic_string/operations/compare/wchar_t/1.cc:
            Likewise.
            * testsuite/experimental/string_view/operations/compare/wchar_t/1.cc:
            Likewise.
    
    (cherry picked from commit 8d8e8f3ad567c7bd1de708fcc841f691d9686c4d)

Diff:
---
 .../testsuite/21_strings/basic_string/modifiers/append/wchar_t/1.cc   | 2 +-
 .../testsuite/21_strings/basic_string/operations/compare/wchar_t/1.cc | 4 ++--
 .../experimental/string_view/operations/compare/wchar_t/1.cc          | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/modifiers/append/wchar_t/1.cc b/libstdc++-v3/testsuite/21_strings/basic_string/modifiers/append/wchar_t/1.cc
index bb2d682de8e..684209f143e 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/modifiers/append/wchar_t/1.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/modifiers/append/wchar_t/1.cc
@@ -117,7 +117,7 @@ void test01(void)
   VERIFY( str06 == L"corpus, corpus" );
 
   str06 = str02;
-  str06.append(L"corpus, ", 12);
+  str06.append(L"corpus, ", 9); // n=9 includes null terminator
   VERIFY( str06 != L"corpus, corpus, " );
 
 
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/operations/compare/wchar_t/1.cc b/libstdc++-v3/testsuite/21_strings/basic_string/operations/compare/wchar_t/1.cc
index 27836f8e6fb..6f2113fb16a 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/operations/compare/wchar_t/1.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/operations/compare/wchar_t/1.cc
@@ -81,8 +81,8 @@ test01()
   test_value(wcsncmp(str_1.data(), str_0.data(), 6), z);
   test_value(wcsncmp(str_1.data(), str_0.data(), 14), lt);
   test_value(wmemcmp(str_1.data(), str_0.data(), 6), z);
-  test_value(wmemcmp(str_1.data(), str_0.data(), 14), lt);
-  test_value(wmemcmp(L"costa marbella", L"costa rica", 14), lt);
+  test_value(wmemcmp(str_1.data(), str_0.data(), 10), lt);
+  test_value(wmemcmp(L"costa marbella", L"costa rica", 10), lt);
 
   // int compare(const basic_string& str) const;
   test_value(str_0.compare(str_1), gt); //because r>m
diff --git a/libstdc++-v3/testsuite/experimental/string_view/operations/compare/wchar_t/1.cc b/libstdc++-v3/testsuite/experimental/string_view/operations/compare/wchar_t/1.cc
index db523e6a83c..20bb030970b 100644
--- a/libstdc++-v3/testsuite/experimental/string_view/operations/compare/wchar_t/1.cc
+++ b/libstdc++-v3/testsuite/experimental/string_view/operations/compare/wchar_t/1.cc
@@ -81,8 +81,8 @@ test01()
   test_value(wcsncmp(str_1.data(), str_0.data(), 6), z);
   test_value(wcsncmp(str_1.data(), str_0.data(), 14), lt);
   test_value(wmemcmp(str_1.data(), str_0.data(), 6), z);
-  test_value(wmemcmp(str_1.data(), str_0.data(), 14), lt);
-  test_value(wmemcmp(L"costa marbella", L"costa rica", 14), lt);
+  test_value(wmemcmp(str_1.data(), str_0.data(), 10), lt);
+  test_value(wmemcmp(L"costa marbella", L"costa rica", 10), lt);
 
   // int compare(const basic_string_view& str) const;
   test_value(str_0.compare(str_1), gt); //because r>m