avoid multiple reallocations in wxString::PrintfV() if vsnprintf() returns the total...

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@36303 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

diff --git a/src/common/string.cpp b/src/common/string.cpp
index c2abb44c199f66bed3f20588f222ddae563a9827..5bb461cb176b4f019fd5609950f8d2b4c09c2e36 100644 (file)
--- a/src/common/string.cpp
+++ b/src/common/string.cpp
@@ -1813,7 +1813,7 @@ int wxString::PrintfV(const wxChar* pszFormat, va_list argptr)
     for ( ;; )
     {
         wxStringBuffer tmp(*this, size + 1);
     for ( ;; )
     {
         wxStringBuffer tmp(*this, size + 1);

-        wxChar* buf = tmp;
+        wxChar *buf = tmp;

 
         if ( !buf )
         {
 
         if ( !buf )
         {


@@ -1836,14 +1836,20 @@ int wxString::PrintfV(const wxChar* pszFormat, va_list argptr)
         // vsnprintf() may return either -1 (traditional Unix behaviour) or the
         // total number of characters which would have been written if the
         // buffer were large enough (newer standards such as Unix98)
         // vsnprintf() may return either -1 (traditional Unix behaviour) or the
         // total number of characters which would have been written if the
         // buffer were large enough (newer standards such as Unix98)

-        if ( len >= 0 && len <= size )
+        if ( len < 0 )
+        {
+            // still not enough, as we don't know how much we need, double the
+            // current size of the buffer
+            size *= 2;
+        }
+        else if ( len > size )
+        {
+            size = len;
+        }
+        else // ok, there was enough space

         {
         {

-            // ok, there was enough space

             break;
         }
             break;
         }

-
-        // still not enough, double it again
-        size *= 2;

     }
 
     // we could have overshot
     }
 
     // we could have overshot