File xbgi-sequence.diff of Package libXbgi

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File xbgi-sequence.diff of Package libXbgi

From: Jan Engelhardt <jengelh@inai.de>
Date: 2014-01-23 14:42:25.612279578 +0100

bgidemo: resolve invocation of undefined behavior near i=++i

rpmlint says:
I: Program causes undefined operation
   (likely same variable used twiceand post/pre incremented in the same expression).
   e.g. x = x++; Split it in two operations.
W: libXbgi sequence-point bgidemo.c:534, 1116

gcc had to say:
bgidemo.c: In function 'ColorDemo':
bgidemo.c:534:13: warning: operation on 'color' may be undefined [-Wsequence-point]
       color = ++color % MaxColors; /* Advance to the next color */
             ^
bgidemo.c: In function 'UserLineStyleDemo':
bgidemo.c:1116:7: warning: operation on 'i' may be undefined [-Wsequence-point]
     i = ++i % 16;   /* Advance to next bit pattern */
       ^

---
 src/test/bgidemo.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: xbgi-364/src/test/bgidemo.c
===================================================================
--- xbgi-364.orig/src/test/bgidemo.c
+++ xbgi-364/src/test/bgidemo.c
@@ -531,7 +531,7 @@ void ColorDemo(void)
       itoa( color, cnum, 10 );		/* Convert # to ASCII		*/
       outtextxy( x+(width/2), y+height+4, cnum );  /* Show color #	*/
 
-      color = ++color % MaxColors;	/* Advance to the next color	*/
+      color = (color + 1) % MaxColors;	/* Advance to the next color	*/
       x += (width / 2) * 3;		/* move the column base 	*/
     }				/* End of Column loop		*/
 
@@ -1113,7 +1113,7 @@ void UserLineStyleDemo(void)
     line( x, y, x, h-y );		/* Draw the new line pattern	*/
 
     x += 5;				/* Move the X location of line	*/
-    i = ++i % 16;			/* Advance to next bit pattern	*/
+    i = (i + 1) % 16;			/* Advance to next bit pattern	*/
 
     if( style == 0xffff ){		/* Are all bits set?		*/
       flag = FALSE;			/*   begin removing bits	*/

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File xbgi-sequence.diff of Package libXbgi

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