Bug 135579 - small interlaced PNGs not decoded correctly.

Patch from randeg@alum.rpi.edu, rs=tor.

modules/libimg/png/MOZCHANGES

@@ -2,7 +2,8 @@
 Changes made to pristine png source by mozilla.org developers.
 
 2002/02/15  -- Synced with 1.0.9 tree
-Reapplied following changes:
+
+Following changes applied:
 
 Bug 78649 - Wrapped stderr fprintfs inside DEBUG ifdef.
 	Affected files: pnggccrd.c, ipng.cpp, if.cpp
@@ -10,3 +11,6 @@ Bug 78649 - Wrapped stderr fprintfs inside DEBUG ifdef.
 Bug 81794 - crash/leak fix for pngrutil.c
 	Affected files: pngrutil.c
 
+Bug 135579 - small interlaced PNG images not decoded correctly.
+	Affected files: pngpread.c
+

modules/libimg/png/pngpread.c

@@ -796,6 +796,19 @@ png_push_process_row(png_structp png_ptr)
                   png_read_push_finish_row(png_ptr);
                }
             }
+	    if (png_ptr->pass == 4 && png_ptr->height <= 4)
+	    {
+	        for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+                {
+                   png_push_have_row(png_ptr, NULL);
+                   png_read_push_finish_row(png_ptr);
+                }
+            }
+            if (png_ptr->pass == 6 && png_ptr->height <= 4)
+            {
+                png_push_have_row(png_ptr, NULL);
+                png_read_push_finish_row(png_ptr);
+            }
             break;
          }
          case 1: