From: Paolo Carlini <pcarlini@suse.de>
Date: Mon, 18 Jul 2005 18:31:59 +0000 (+0000)
Subject: re PR libstdc++/21286 (filebuf::xsgetn vs pipes)
X-Git-Tag: releases/gcc-3.4.5~322
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=996cfab1427cf3b6724f36f5eeadb290f919e95e;p=thirdparty%2Fgcc.git

re PR libstdc++/21286 (filebuf::xsgetn vs pipes)

2005-07-18  Paolo Carlini  <pcarlini@suse.de>
	    Nathan Myers  <ncm@cantrip.org>

	PR libstdc++/21286
	* include/bits/fstream.tcc (basic_filebuf<>::xsgetn):
	Loop on short reads.

Co-Authored-By: Nathan Myers <ncm@cantrip.org>

From-SVN: r102138
---

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 72851fae9444..6e645d79c149 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,10 @@
+2005-07-18  Paolo Carlini  <pcarlini@suse.de>
+	    Nathan Myers  <ncm@cantrip.org>
+
+	PR libstdc++/21286
+	* include/bits/fstream.tcc (basic_filebuf<>::xsgetn):
+	Loop on short reads.
+
 2005-05-27  Mark Mitchell  <mark@codesourcery.com>
 
 	* testsuite/Makefile.in: Regenerate with Automake 1.7.8.
diff --git a/libstdc++-v3/include/bits/fstream.tcc b/libstdc++-v3/include/bits/fstream.tcc
index 25a4d48cb720..3b433ea79b05 100644
--- a/libstdc++-v3/include/bits/fstream.tcc
+++ b/libstdc++-v3/include/bits/fstream.tcc
@@ -535,13 +535,28 @@ namespace std
 	       __n -= __avail;
 	     }
 
-	   const streamsize __len = _M_file.xsgetn(reinterpret_cast<char*>(__s),
-						   __n);
-	   if (__len == -1)
-	     __throw_ios_failure(__N("basic_filebuf::xsgetn "
-				     "error reading the file"));
-	   __ret += __len;
-	   if (__len == __n)
+	   // Need to loop in case of short reads (relatively common
+	   // with pipes).
+	   streamsize __len;
+	   for (;;)
+	     {
+	       __len = _M_file.xsgetn(reinterpret_cast<char*>(__s),
+				      __n);
+	       if (__len == -1)
+		 __throw_ios_failure(__N("basic_filebuf::xsgetn "
+					 "error reading the file"));
+	       if (__len == 0)
+		 break;
+
+	       __n -= __len;
+	       __ret += __len;
+	       if (__n == 0)
+		 break;
+
+	       __s += __len;
+	     }
+
+	   if (__n == 0)
 	     {
 	       _M_set_buffer(0);
 	       _M_reading = true;