commit 5432c01ffd6260d19403ce9c1a09b99ab488485e
author John Bowler <jbowler@acm.org> Sat Feb 12 08:59:17 2011 -0600
committer Glenn Randers-Pehrson <glennrp@shaggy.simplesystems.org> Sat Feb 12 08:59:17 2011 -0600
tree 25d86ed1b82c662b81c02d3b9502f89ad36b7726
parent 9c69360e97a305703f9cbcfa78a2526a228bfa43

[devel] Fix png_get_current_row_number in the interlaced case.

png.h

diff --git a/png.h b/png.h
index d50c031..5d69f0f 100644
--- a/png.h
+++ b/png.h
@@ -1477,6 +1477,10 @@
  * row number is still the row in the final, de-interlaced, image but the row
  * only contains the data of the current pass - consult png_row_info for the
  * actual width of the row!
+ *
+ * In contrast the row numbers passed to the progressive reader and sequential
+ * reader callbacks are actually the rows in the input data - so the row in the
+ * interlaced pass for an interlaced image.
  */
 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structp));
 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structp));

pngtrans.c

diff --git a/pngtrans.c b/pngtrans.c
index 137f555..89661ad 100644
--- a/pngtrans.c
+++ b/pngtrans.c
@@ -703,11 +703,21 @@
 }
 #endif
 
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
 png_uint_32 PNGAPI
 png_get_current_row_number(png_const_structp png_ptr)
 {
+   /* This API returns the row in output, not the input row: */
    if (png_ptr != NULL)
-      return png_ptr->row_number;
+   {
+      if (png_ptr->interlaced == PNG_INTERLACE_NONE)
+         return png_ptr->row_number;
+      else if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+         return PNG_ROW_FROM_PASS_ROW(png_ptr->row_number, png_ptr->pass);
+
+      /* Else something bad is happening: */
+   }
+
    return PNG_UINT_32_MAX; /* help the app not to fail silently */
 }
 
@@ -718,6 +728,7 @@
       return png_ptr->pass;
    return 8; /* invalid */
 }
+#endif /* PNG_USER_TRANSFORM_INFO_SUPPORTED */
 #endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||
           PNG_WRITE_USER_TRANSFORM_SUPPORTED */
 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */

pngvalid.c

diff --git a/pngvalid.c b/pngvalid.c
index 8724420..417d71b 100644
--- a/pngvalid.c
+++ b/pngvalid.c
@@ -3072,7 +3072,13 @@
        * us the y in the sub-image:
        */
       if (dp->do_interlace && dp->interlace_type == PNG_INTERLACE_ADAM7)
+      {
+         if (pass != png_get_current_pass_number(pp))
+            png_error(pp, "png_get_current_pass_number is broken");
          y = PNG_ROW_FROM_PASS_ROW(y, pass);
+         if (y != png_get_current_row_number(pp))
+            png_error(pp, "png_get_current_row_number is broken");
+      }
 
       /* Validate this just in case. */
       if (y >= dp->h)

scripts/pnglibconf.h.prebuilt

diff --git a/scripts/pnglibconf.h.prebuilt b/scripts/pnglibconf.h.prebuilt
index b1d2169..de1c4d3 100644
--- a/scripts/pnglibconf.h.prebuilt
+++ b/scripts/pnglibconf.h.prebuilt
@@ -148,6 +148,7 @@
 #define PNG_WRITE_INVERT_ALPHA_SUPPORTED
 #define PNG_sCAL_SUPPORTED
 #define PNG_WRITE_zTXt_SUPPORTED
+#define PNG_USER_TRANSFORM_INFO_SUPPORTED
 #define PNG_sBIT_SUPPORTED
 #define PNG_cHRM_SUPPORTED
 #define PNG_bKGD_SUPPORTED
@@ -155,7 +156,6 @@
 #define PNG_WRITE_iTXt_SUPPORTED
 #define PNG_oFFs_SUPPORTED
 #define PNG_USER_TRANSFORM_PTR_SUPPORTED
-#define PNG_USER_TRANSFORM_INFO_SUPPORTED
 #define PNG_hIST_SUPPORTED
 #define PNG_iCCP_SUPPORTED
 #define PNG_sRGB_SUPPORTED