From ced70ebaa372945ec8d73703d81e4a10d6d51c9b Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Tue, 10 Nov 2020 15:46:02 +0000
Subject: [PATCH] libstdc++: Fix more unspecified comparisons to null pointer
[PR 97415]
This adds some more null checks to avoid a relational comparison with a
null pointer, similar to 78198b6021a9695054dab039340202170b88423c.
libstdc++-v3/ChangeLog:
PR libstdc++/97415
* include/std/sstream (basic_stringbuf::_M_update_egptr)
(basic_stringbuf::__xfer_bufptrs::__xfer_bufptrs): Check for
null before comparing pointers.
---
libstdc++-v3/include/std/sstream | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/libstdc++-v3/include/std/sstream b/libstdc++-v3/include/std/sstream
index 437e2ba2a5f8..9c50e4e83281 100644
--- a/libstdc++-v3/include/std/sstream
+++ b/libstdc++-v3/include/std/sstream
@@ -357,13 +357,16 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
void
_M_update_egptr()
{
- const bool __testin = _M_mode & ios_base::in;
- if (this->pptr() && this->pptr() > this->egptr())
+ if (char_type* __pptr = this->pptr())
{
- if (__testin)
- this->setg(this->eback(), this->gptr(), this->pptr());
- else
- this->setg(this->pptr(), this->pptr(), this->pptr());
+ char_type* __egptr = this->egptr();
+ if (!__egptr || __pptr > __egptr)
+ {
+ if (_M_mode & ios_base::in)
+ this->setg(this->eback(), this->gptr(), __pptr);
+ else
+ this->setg(__pptr, __pptr, __pptr);
+ }
}
}
@@ -396,7 +399,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
_M_poff[0] = __from.pbase() - __str;
_M_poff[1] = __from.pptr() - __from.pbase();
_M_poff[2] = __from.epptr() - __str;
- if (__from.pptr() > __end)
+ if (!__end || __from.pptr() > __end)
__end = __from.pptr();
}
--
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