Patch:
From 7b2704987e4cca85e56c41947c38a4bedd8bc0f9 Mon Sep 17 00:00:00 2001
From: Dennis Kasprzyk <onestone@opencompositing.org>
Date: Mon, 25 Jun 2007 14:14:32 +0200
Subject: [PATCH] Added string formating to fragment functions.

---
 include/compiz.h |    8 +++++---
 src/fragment.c   |   43 +++++++++++++++++++++++++++++++++++++++----
 2 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/include/compiz.h b/include/compiz.h
index dd34f00..4c66c55 100644
--- a/include/compiz.h
+++ b/include/compiz.h
@@ -26,7 +26,7 @@
 #ifndef _COMPIZ_H
 #define _COMPIZ_H

-#define ABIVERSION 20070606
+#define ABIVERSION 20070625

 #include <stdio.h>
 #include <sys/time.h>
@@ -3008,11 +3008,13 @@ addColorOpToFunctionData (CompFunctionData *data,

 Bool
 addDataOpToFunctionData (CompFunctionData *data,
-                        char             *str);
+                        char             *str,
+                        ...);

 Bool
 addBlendOpToFunctionData (CompFunctionData *data,
-                         char             *str);
+                         char             *str,
+                         ...);

 int
 createFragmentFunction (CompScreen      *s,
diff --git a/src/fragment.c b/src/fragment.c
index 1c35858..4090c90 100644
--- a/src/fragment.c
+++ b/src/fragment.c
@@ -34,6 +34,8 @@
 #define COMP_FUNCTION_ARB_MASK (1 << 0)
 #define COMP_FUNCTION_MASK     (COMP_FUNCTION_ARB_MASK)

+#define BUFFER_SIZE 1024
+
 struct _CompProgram {
     struct _CompProgram *next;

@@ -1031,25 +1033,58 @@ addColorOpToFunctionData (CompFunctionData *data,

 Bool
 addDataOpToFunctionData (CompFunctionData *data,
-                        char             *str)
+                        char             *str,
+                        ...)
 {
-    int index = data->nBody;
+    int     index = data->nBody;
+    int     n;
+    char    fStr[BUFFER_SIZE];
+    va_list ap;
+
+    va_start (ap, str);
+
+    n = snprintf (fStr, BUFFER_SIZE, str, ap);
+
+    va_end (ap);

+    if (n < 0 || n >= BUFFER_SIZE)
+    {
+       compLogMessage (NULL, "core", CompLogLevelError,
+                       "failed to add fragment data operation.");
+       return FALSE;
+    }
     if (!allocBodyOpInFunctionData (data))
        return FALSE;

     data->body[index].type     = CompOpTypeData;
-    data->body[index].data.data = strdup (str);
+    data->body[index].data.data = strdup (fStr);

     return TRUE;
 }

 Bool
 addBlendOpToFunctionData (CompFunctionData *data,
-                         char             *str)
+                         char             *str,
+                         ...)
 {
     int index = data->nBody;
+    int     n;
+    char    fStr[BUFFER_SIZE];
+    va_list ap;
+
+    va_start (ap, str);

+    n = snprintf (fStr, BUFFER_SIZE, str, ap);
+
+    va_end (ap);
+
+    if (n < 0 || n >= BUFFER_SIZE)
+    {
+       compLogMessage (NULL, "core", CompLogLevelError,
+                       "failed to add fragment blend operation.");
+       return FALSE;
+    }
+
     if (!allocBodyOpInFunctionData (data))
        return FALSE;

--
1.5.0.5-dirty

Blur code:

Funktioniert:
 ok &= addDataOpToFunctionData (data,
		      "MUL coord, fragment.position, program.env[%d];",
		      param);

Funktioniert nicht:
	    ok &= addDataOpToFunctionData (data,
		      "ADD t0, coord, program.env[%d];"
		      "TEX s0, t0, texture[%d], %s;"

		      "SUB t1, coord, program.env[%d];"
		      "TEX s1, t1, texture[%d], %s;"

		      "MAD t2, program.env[%d], { -1.0, 1.0, 0.0, 0.0 }, coord;"
		      "TEX s2, t2, texture[%d], %s;"

		      "MAD t3, program.env[%d], { 1.0, -1.0, 0.0, 0.0 }, coord;"
		      "TEX s3, t3, texture[%d], %s;"

		      "MUL_SAT mask, output.a, program.env[%d];"

		      "MUL sum, s0, 0.25;"
		      "MAD sum, s1, 0.25, sum;"
		      "MAD sum, s2, 0.25, sum;"
		      "MAD sum, s3, 0.25, sum;",

		      param + 2, unit, targetString,
		      param + 2, unit, targetString,
		      param + 2, unit, targetString,
		      param + 2, unit, targetString,
		      param + 1);

Crash:
#2  0x00002aaaab49d556 in crash_handler (sig=11) at crashhandler.c:50
#3  <signal handler called>
#4  0x00002b970d3e8d70 in strlen () from /lib64/libc.so.6
#5  0x00002b970d3ba34f in vfprintf () from /lib64/libc.so.6
#6  0x00002b970d3db74a in vsnprintf () from /lib64/libc.so.6
#7  0x00002b970d3bfc83 in snprintf () from /lib64/libc.so.6
#8  0x0000000000426eb9 in addDataOpToFunctionData (data=0x978330, str=0x7fffa06de2b8 "\002") at fragment.c:1046
#9  0x00002aaaad7ced31 in getDstBlurFragmentFunction (s=0x7c4ae0, texture=<value optimized out>, param=0, unit=1)
    at blur.c:1125
#10 0x00002aaaad7cf8cb in blurDrawWindowTexture (w=0x8e5300, texture=0x8e4f40, attrib=<value optimized out>, mask=589824)
    at blur.c:2059
#11 0x0000000000421104 in drawWindow (w=0x8e5300, transform=<value optimized out>, fragment=0x7fffa06dfc50,
    region=0x8e4fe0, mask=589824) at paint.c:1014
...