Re: kdiff3: FTBFS on hurd-i386 (for review)

[Svante Signell]

Hi Pino

On Thu, 2014-09-25 at 10:08 +0200, Pino Toscano wrote:
> On 2014-09-24 19:11, Philipp A. Hartmann wrote:
> > I would probably do it like this (untested):
> >
> >     const char *path =
> >         QFile::encodeName(fi.absoluteFilePath()).constData();
> 
> QFile::encodeName returns a temporary QByteArray, and getting a
> pointer to its internal char* will cause it to be a dangling pointer.
> 
>    const QByteArray path = QFile::encodeName(fi.absoluteFilePath());
> 
> and then use path.constData() whenever needed.
> 
> >         std::vector<char> s(sb.st_size + 1);
> 
> Please use QByteArray instead.

Ok now?

Index: kdiff3-0.9.98/src-QT4/fileaccess.cpp
===================================================================
--- kdiff3-0.9.98.orig/src-QT4/fileaccess.cpp
+++ kdiff3-0.9.98/src-QT4/fileaccess.cpp
@@ -235,14 +235,22 @@ void FileAccess::setFile( const QFileInf
          d()->m_linkTarget = fi.readLink();
 #else
          // Unfortunately Qt4 readLink always returns an absolute path, even if the link is relative
-         char s[PATH_MAX+1];
-         int len = readlink(QFile::encodeName(fi.absoluteFilePath()).constData(), s, PATH_MAX);
-         if ( len>0 )
+         const QByteArray path = QFile::encodeName(fi.absoluteFilePath());
+         struct stat sb;
+         bool resolved = false;
+
+         if ( lstat(path.constData(), &sb) != -1 )
          {
-            s[len] = '\0';
-            d()->m_linkTarget = QFile::decodeName(s);
+            std::vector<char> s(sb.st_size + 1);
+            ssize_t len = readlink(path.constData(), &s[0], s.size());
+            if ( len > 0 && len <= sb.st_size )
+            {
+               resolved = true;
+               s[len] = '\0';
+               d()->m_linkTarget = QFile::decodeName(&s[0]);
+            }
          }
-         else
+         if ( !resolved )
          {
             d()->m_linkTarget = fi.readLink();
          }