Don't create multiple XPrint or PostScript device contexts -- the

contexts share globals and are careless... Bug 127627, patch by Roland
Mainz <Roland.Mainz@informatik.med.uni-giessen.de>, r=bryner,rods,
sr=jag, a=asa

gfx/src/ps/nsDeviceContextPS.cpp

@@ -36,6 +36,14 @@
  * the terms of any one of the NPL, the GPL or the LGPL.
  *
  * ***** END LICENSE BLOCK ***** */
+ 
+/* PostScript/Xprint print modules do not support more than one object
+ * instance because they use global vars which cannot be shared between
+ * multiple instances...
+ * bug 119491 ("Cleanup global vars in PostScript and Xprint modules) will fix
+ * that...
+ */
+#define WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS 1
 
 #include "nsDeviceContextPS.h"
 #include "nsRenderingContextPS.h"
@@ -43,6 +51,10 @@
 #include "nsFontMetricsPS.h"
 #include "nsPostScriptObj.h"
 
+#ifdef WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS
+static int instance_counter = 0;
+#endif /* WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS */
+
 /** ---------------------------------------------------
  *  See documentation in nsIDeviceContext.h
  *	@update 12/21/98 dwc
@@ -52,6 +64,11 @@ nsDeviceContextPS :: nsDeviceContextPS()
 {
   mSpec = nsnull; 
   mParentDeviceContext = nsnull;
+  
+#ifdef WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS
+  instance_counter++;
+  NS_ASSERTION(instance_counter < 2, "Cannot have more than one print device context.");
+#endif /* WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS */
 }
 
 /** ---------------------------------------------------
@@ -63,6 +80,11 @@ nsDeviceContextPS :: ~nsDeviceContextPS()
   /* nsCOMPtr<> will dispose the objects... */
   mSpec = nsnull;
   mParentDeviceContext = nsnull;
+
+#ifdef WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS
+  instance_counter--;
+  NS_ASSERTION(instance_counter >= 0, "We cannot have less than zero instances.");
+#endif /* WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS */
 }
 
 NS_IMETHODIMP
@@ -70,6 +92,13 @@ nsDeviceContextPS :: SetSpec(nsIDeviceContextSpec* aSpec)
 {
   nsresult  rv = NS_ERROR_FAILURE;
 
+#ifdef WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS
+  NS_ASSERTION(instance_counter < 2, "Cannot have more than one print device context.");
+  if (instance_counter > 1) {
+    return NS_ERROR_GFX_PRINTER_PRINT_WHILE_PREVIEW;
+  }
+#endif /* WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS */
+
   mSpec = aSpec;
   
   nsCOMPtr<nsIDeviceContextSpecPS> psSpec;
@@ -100,6 +129,13 @@ nsDeviceContextPS::InitDeviceContextPS(nsIDeviceContext *aCreatingDeviceContext,
 float origscale, newscale;
 float t2d, a2d;
 
+#ifdef WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS
+  NS_ASSERTION(instance_counter < 2, "Cannot have more than one print device context.");
+  if (instance_counter > 1) {
+    return NS_ERROR_GFX_PRINTER_PRINT_WHILE_PREVIEW;
+  }
+#endif /* WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS */
+
   mDepth = 1;     // just for arguments sake
 
   mTwipsToPixels = (float)72.0/(float)NSIntPointsToTwips(72);

gfx/src/xprint/nsDeviceContextXP.cpp

@@ -38,6 +38,14 @@
  *
  * ***** END LICENSE BLOCK ***** */
  
+/* PostScript/Xprint print modules do not support more than one object
+ * instance because they use global vars which cannot be shared between
+ * multiple instances...
+ * bug 119491 ("Cleanup global vars in PostScript and Xprint modules) will fix
+ * that...
+ */
+#define WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS 1 
+ 
 #include "nsDeviceContextXP.h"
 #include "nsRenderingContextXp.h"
 #include "nsFontMetricsXlib.h"
@@ -50,6 +58,10 @@
 static PRLogModuleInfo *nsDeviceContextXpLM = PR_NewLogModule("nsDeviceContextXp");
 #endif /* PR_LOGGING */
 
+#ifdef WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS
+static int instance_counter = 0;
+#endif /* WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS */
+
 /** ---------------------------------------------------
  *  See documentation in nsIDeviceContext.h
  */
@@ -59,6 +71,11 @@ nsDeviceContextXp :: nsDeviceContextXp()
   mPrintContext        = nsnull;
   mSpec                = nsnull; 
   mParentDeviceContext = nsnull;
+  
+#ifdef WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS
+  instance_counter++;
+  NS_ASSERTION(instance_counter < 2, "Cannot have more than one print device context.");
+#endif /* WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS */
 }
 
 /** ---------------------------------------------------
@@ -68,6 +85,11 @@ nsDeviceContextXp :: nsDeviceContextXp()
 nsDeviceContextXp :: ~nsDeviceContextXp() 
 { 
   DestroyXPContext();
+
+#ifdef WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS
+  instance_counter--;
+  NS_ASSERTION(instance_counter >= 0, "We cannot have less than zero instances.");
+#endif /* WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS */
 }
 
 
@@ -75,9 +97,15 @@ NS_IMETHODIMP
 nsDeviceContextXp::SetSpec(nsIDeviceContextSpec* aSpec)
 {
   nsresult  rv = NS_ERROR_FAILURE;
-
   PR_LOG(nsDeviceContextXpLM, PR_LOG_DEBUG, ("nsDeviceContextXp::SetSpec()\n"));
 
+#ifdef WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS
+  NS_ASSERTION(instance_counter < 2, "Cannot have more than one print device context.");
+  if (instance_counter > 1) {
+    return NS_ERROR_GFX_PRINTER_PRINT_WHILE_PREVIEW;
+  }
+#endif /* WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS */
+
   nsCOMPtr<nsIDeviceContextSpecXp> xpSpec;
 
   mSpec = aSpec;
@@ -114,6 +142,13 @@ nsDeviceContextXp::InitDeviceContextXP(nsIDeviceContext *aCreatingDeviceContext,
   float t2d, a2d;
   int   print_resolution;
 
+#ifdef WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS
+  NS_ASSERTION(instance_counter < 2, "Cannot have more than one print device context.");
+  if (instance_counter > 1) {
+    return NS_ERROR_GFX_PRINTER_PRINT_WHILE_PREVIEW;
+  }
+#endif /* WE_DO_NOT_SUPPORT_MULTIPLE_PRINT_DEVICECONTEXTS */
+
   mPrintContext->GetPrintResolution(print_resolution);
 
   mPixelsToTwips = (float)NSIntPointsToTwips(72) / (float)print_resolution;