[libpng16] Reverted use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING

in the manual, example.c, pngtest.c, and applications in the contrib directory.
It was incorrect advice.
diff --git a/ANNOUNCE b/ANNOUNCE
index 686f080..bbf725f 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -62,6 +62,9 @@
     warnings go away.
 
 Version 1.6.15beta06 [November 6, 2014]
+  Reverted use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING
+    in example.c, pngtest.c, and applications in the contrib directory.
+    It was incorrect advice.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index e63d805..2f9a3b7 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5070,6 +5070,9 @@
     warnings go away.
 
 Version 1.6.15beta06 [November 6, 2014]
+  Reverted use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING
+    in example.c, pngtest.c, and applications in the contrib directory.
+    It was incorrect advice.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/contrib/examples/iccfrompng.c b/contrib/examples/iccfrompng.c
index cfea086..386e522 100644
--- a/contrib/examples/iccfrompng.c
+++ b/contrib/examples/iccfrompng.c
@@ -32,7 +32,7 @@
 static png_bytep
 extract(FILE *fp, png_uint_32 *proflen)
 {
-   png_structp png_ptr = png_create_read_struct(png_get_libpng_ver(NULL),0,0,0);
+   png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
    png_infop info_ptr = NULL;
    png_bytep result = NULL;
 
diff --git a/contrib/examples/pngpixel.c b/contrib/examples/pngpixel.c
index 9880124..e0d43e3 100644
--- a/contrib/examples/pngpixel.c
+++ b/contrib/examples/pngpixel.c
@@ -161,7 +161,7 @@
           * writes error messages to stderr.  Creating the png_struct is a
           * little tricky; just copy the following code.
           */
-         png_structp png_ptr = png_create_read_struct(png_get_libpng_ver(NULL),
+         png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
             NULL, NULL, NULL);
 
          if (png_ptr != NULL)
diff --git a/contrib/libtests/makepng.c b/contrib/libtests/makepng.c
index 6bfd8e6..9f11b29 100644
--- a/contrib/libtests/makepng.c
+++ b/contrib/libtests/makepng.c
@@ -556,7 +556,7 @@
    volatile png_fixed_point gamma, chunk_insert * volatile insert,
    unsigned int filters, unsigned int *colors)
 {
-   png_structp png_ptr = png_create_write_struct(png_get_libpng_ver(NULL),
+   png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
       name, makepng_error, makepng_warning);
    volatile png_infop info_ptr = NULL;
    volatile png_bytep row = NULL;
diff --git a/contrib/libtests/pngimage.c b/contrib/libtests/pngimage.c
index 957f61c..dccfbce 100644
--- a/contrib/libtests/pngimage.c
+++ b/contrib/libtests/pngimage.c
@@ -826,7 +826,7 @@
       dp->transforms = transforms;
    }
 
-   dp->read_pp = pp = png_create_read_struct(png_get_libpng_ver(NULL), dp,
+   dp->read_pp = pp = png_create_read_struct(PNG_LIBPNG_VER_STRING, dp,
       display_error, display_warning);
    if (pp == NULL)
       display_log(dp, LIBPNG_ERROR, "failed to create read struct");
@@ -1271,7 +1271,7 @@
    dp->operation = "write";
    dp->transforms = transforms;
 
-   dp->write_pp = png_create_write_struct(png_get_libpng_ver(NULL), dp,
+   dp->write_pp = png_create_write_struct(PNG_LIBPNG_VER_STRING, dp,
       display_error, display_warning);
 
    if (dp->write_pp == NULL)
diff --git a/contrib/libtests/pngunknown.c b/contrib/libtests/pngunknown.c
index ada0fb5..b8c4899 100644
--- a/contrib/libtests/pngunknown.c
+++ b/contrib/libtests/pngunknown.c
@@ -651,7 +651,7 @@
    /* Some of these errors are permanently fatal and cause an exit here, others
     * are per-test and cause an error return.
     */
-   d->png_ptr = png_create_read_struct(png_get_libpng_ver(NULL), d, error,
+   d->png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, d, error,
       warning);
    if (d->png_ptr == NULL)
    {
diff --git a/contrib/libtests/pngvalid.c b/contrib/libtests/pngvalid.c
index d6a50c8..a93fe65 100644
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@@ -1559,7 +1559,7 @@
        */
 #     ifdef PNG_USER_MEM_SUPPORTED
          if (!ps->speed)
-            ps->pwrite = png_create_write_struct_2(png_get_libpng_ver(NULL),
+            ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING,
                ps, store_error, store_warning, &ps->write_memory_pool,
                store_malloc, store_free);
 
@@ -1680,13 +1680,13 @@
     */
 #  ifdef PNG_USER_MEM_SUPPORTED
       if (!ps->speed)
-         ps->pread = png_create_read_struct_2(png_get_libpng_ver(NULL), ps,
+         ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps,
              store_error, store_warning, &ps->read_memory_pool, store_malloc,
              store_free);
 
       else
 #  endif
-   ps->pread = png_create_read_struct(png_get_libpng_ver(NULL), ps, store_error,
+   ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps, store_error,
       store_warning);
 
    if (ps->pread == NULL)
diff --git a/contrib/libtests/readpng.c b/contrib/libtests/readpng.c
index 6685513..7ba46d0 100644
--- a/contrib/libtests/readpng.c
+++ b/contrib/libtests/readpng.c
@@ -34,7 +34,7 @@
 static int
 read_png(FILE *fp)
 {
-   png_structp png_ptr = png_create_read_struct(png_get_libpng_ver(NULL),0,0,0);
+   png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
    png_infop info_ptr = NULL;
    png_bytep row = NULL, display = NULL;
 
diff --git a/contrib/libtests/timepng.c b/contrib/libtests/timepng.c
index b858184..7c93797 100644
--- a/contrib/libtests/timepng.c
+++ b/contrib/libtests/timepng.c
@@ -37,7 +37,7 @@
 
 static int read_png(FILE *fp)
 {
-   png_structp png_ptr = png_create_read_struct(png_get_libpng_ver(NULL),0,0,0);
+   png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
    png_infop info_ptr = NULL;
    png_bytep row = NULL, display = NULL;
 
diff --git a/example.c b/example.c
index aeb3735..f8067b9 100644
--- a/example.c
+++ b/example.c
@@ -294,7 +294,7 @@
     * the compiler header file version, so that we know if the application
     * was compiled with a compatible version of the library.  REQUIRED
     */
-   png_ptr = png_create_read_struct(png_get_libpng_ver(NULL),
+   png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
       png_voidp user_error_ptr, user_error_fn, user_warning_fn);
 
    if (png_ptr == NULL)
@@ -613,7 +613,7 @@
     * the library version is compatible in case we are using dynamically
     * linked libraries.
     */
-   *png_ptr = png_create_read_struct(png_get_libpng_ver(NULL),
+   *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
        png_voidp user_error_ptr, user_error_fn, user_warning_fn);
 
    if (*png_ptr == NULL)
@@ -779,7 +779,7 @@
     * the library version is compatible with the one used at compile time,
     * in case we are using dynamically linked libraries.  REQUIRED.
     */
-   png_ptr = png_create_write_struct(png_get_libpng_ver(NULL),
+   png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
       png_voidp user_error_ptr, user_error_fn, user_warning_fn);
 
    if (png_ptr == NULL)
diff --git a/libpng-manual.txt b/libpng-manual.txt
index f45569b..8b6b467 100644
--- a/libpng-manual.txt
+++ b/libpng-manual.txt
@@ -372,7 +372,7 @@
 create the structure, so your application should check for that.
 
     png_structp png_ptr = png_create_read_struct
-        (png_get_libpng_ver(NULL), (png_voidp)user_error_ptr,
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
         user_error_fn, user_warning_fn);
 
     if (!png_ptr)
@@ -392,7 +392,7 @@
 png_create_read_struct_2() instead of png_create_read_struct():
 
     png_structp png_ptr = png_create_read_struct_2
-        (png_get_libpng_ver(NULL), (png_voidp)user_error_ptr,
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
         user_error_fn, user_warning_fn, (png_voidp)
         user_mem_ptr, user_malloc_fn, user_free_fn);
 
@@ -2486,7 +2486,7 @@
  initialize_png_reader()
  {
     png_ptr = png_create_read_struct
-        (png_get_libpng_ver(NULL), (png_voidp)user_error_ptr,
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
          user_error_fn, user_warning_fn);
 
     if (!png_ptr)
@@ -2694,7 +2694,7 @@
 "read_ptr" and "write_ptr".  Look at pngtest.c, for example.
 
     png_structp png_ptr = png_create_write_struct
-       (png_get_libpng_ver(NULL), (png_voidp)user_error_ptr,
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
         user_error_fn, user_warning_fn);
 
     if (!png_ptr)
@@ -2713,7 +2713,7 @@
 png_create_write_struct_2() instead of png_create_write_struct():
 
     png_structp png_ptr = png_create_write_struct_2
-       (png_get_libpng_ver(NULL), (png_voidp)user_error_ptr,
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
         user_error_fn, user_warning_fn, (png_voidp)
         user_mem_ptr, user_malloc_fn, user_free_fn);
 
diff --git a/libpng.3 b/libpng.3
index 935cdf6..f4ea5d9 100644
--- a/libpng.3
+++ b/libpng.3
@@ -876,7 +876,7 @@
 create the structure, so your application should check for that.
 
     png_structp png_ptr = png_create_read_struct
-        (png_get_libpng_ver(NULL), (png_voidp)user_error_ptr,
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
         user_error_fn, user_warning_fn);
 
     if (!png_ptr)
@@ -896,7 +896,7 @@
 png_create_read_struct_2() instead of png_create_read_struct():
 
     png_structp png_ptr = png_create_read_struct_2
-        (png_get_libpng_ver(NULL), (png_voidp)user_error_ptr,
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
         user_error_fn, user_warning_fn, (png_voidp)
         user_mem_ptr, user_malloc_fn, user_free_fn);
 
@@ -2990,7 +2990,7 @@
  initialize_png_reader()
  {
     png_ptr = png_create_read_struct
-        (png_get_libpng_ver(NULL), (png_voidp)user_error_ptr,
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
          user_error_fn, user_warning_fn);
 
     if (!png_ptr)
@@ -3198,7 +3198,7 @@
 "read_ptr" and "write_ptr".  Look at pngtest.c, for example.
 
     png_structp png_ptr = png_create_write_struct
-       (png_get_libpng_ver(NULL), (png_voidp)user_error_ptr,
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
         user_error_fn, user_warning_fn);
 
     if (!png_ptr)
@@ -3217,7 +3217,7 @@
 png_create_write_struct_2() instead of png_create_write_struct():
 
     png_structp png_ptr = png_create_write_struct_2
-       (png_get_libpng_ver(NULL), (png_voidp)user_error_ptr,
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
         user_error_fn, user_warning_fn, (png_voidp)
         user_mem_ptr, user_malloc_fn, user_free_fn);
 
diff --git a/pngtest.c b/pngtest.c
index f893738..4b19a09 100644
--- a/pngtest.c
+++ b/pngtest.c
@@ -869,11 +869,11 @@
    pngtest_debug("Allocating read and write structures");
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
    read_ptr =
-      png_create_read_struct_2(png_get_libpng_ver(NULL), NULL,
+      png_create_read_struct_2(PNG_LIBPNG_VER_STRING, NULL,
       NULL, NULL, NULL, png_debug_malloc, png_debug_free);
 #else
    read_ptr =
-      png_create_read_struct(png_get_libpng_ver(NULL), NULL, NULL, NULL);
+      png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 #endif
    png_set_error_fn(read_ptr, &error_parameters, pngtest_error,
       pngtest_warning);
@@ -881,11 +881,11 @@
 #ifdef PNG_WRITE_SUPPORTED
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
    write_ptr =
-      png_create_write_struct_2(png_get_libpng_ver(NULL), NULL,
+      png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL,
       NULL, NULL, NULL, png_debug_malloc, png_debug_free);
 #else
    write_ptr =
-      png_create_write_struct(png_get_libpng_ver(NULL), NULL, NULL, NULL);
+      png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 #endif
    png_set_error_fn(write_ptr, &error_parameters, pngtest_error,
       pngtest_warning);