commit d450505a297a26433aea52dbe8107383b303c1c6
author Jamie Madill <jmadill@chromium.org> Mon Feb 24 15:26:49 2014 -0500
committer Jamie Madill <jmadill@chromium.org> Tue Feb 25 20:47:48 2014 +0000
tree ed60dfd57288df683e96a038a6f577b364ead2a1
parent 691bd3e9e0d9bbb41d4f12c28bb77d569fa3993f

Fix long error messages breaking InfoLog::append.

Using two calls to vsnprintf allows us to correctly determine
maximum buffer size as well as fixing garbage characters from
a missing NULL terminator.

Bug report from roland@lagoa.com.

BUG=angle:561

Change-Id: I4eb156342d9106d40783a3cf57c0c1d1889390e2
Reviewed-on: https://chromium-review.googlesource.com/186988
Reviewed-by: Nicolas Capens <nicolascapens@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>

src/libGLESv2/Program.cpp

diff --git a/src/libGLESv2/Program.cpp b/src/libGLESv2/Program.cpp
index a59a0f9..c9da1a3 100644
--- a/src/libGLESv2/Program.cpp
+++ b/src/libGLESv2/Program.cpp
@@ -95,32 +95,36 @@
         return;
     }
 
-    char info[1024];
-
     va_list vararg;
     va_start(vararg, format);
-    vsnprintf(info, sizeof(info), format, vararg);
+    size_t infoLength = vsnprintf(NULL, 0, format, vararg);
     va_end(vararg);
 
-    size_t infoLength = strlen(info);
+    char *logPointer = NULL;
 
     if (!mInfoLog)
     {
         mInfoLog = new char[infoLength + 2];
-        strcpy(mInfoLog, info);
-        strcpy(mInfoLog + infoLength, "\n");
+        logPointer = mInfoLog;
     }
     else
     {
-        size_t logLength = strlen(mInfoLog);
-        char *newLog = new char[logLength + infoLength + 2];
+        size_t currentlogLength = strlen(mInfoLog);
+        char *newLog = new char[currentlogLength + infoLength + 2];
         strcpy(newLog, mInfoLog);
-        strcpy(newLog + logLength, info);
-        strcpy(newLog + logLength + infoLength, "\n");
 
         delete[] mInfoLog;
         mInfoLog = newLog;
+
+        logPointer = mInfoLog + currentlogLength;
     }
+
+    va_start(vararg, format);
+    vsnprintf(logPointer, infoLength, format, vararg);
+    va_end(vararg);
+
+    logPointer[infoLength] = 0;
+    strcpy(logPointer + infoLength, "\n");
 }
 
 void InfoLog::reset()