(re)allow WBMP detection with system libgd

provide getbmi and skipheader not exported functions in gd_compat.

3 files changed, 40 insertions, 4 deletions

diff --git a/ext/gd/gd.c b/ext/gd/gd.c
index 6cafb51f20..203ae24216 100644
--- a/ext/gd/gd.c
+++ b/ext/gd/gd.c
@@ -2403,14 +2403,12 @@ static int _php_image_type (char data[8])
 	} else if (!memcmp(data, php_sig_gif, 3)) {
 		return PHP_GDIMG_TYPE_GIF;
 	}
-/* Temporary disabled, as gdGetC, getmbi and skipheader not exported in system libgd */
-#if HAVE_GD_BUNDLED
 #ifdef HAVE_GD_WBMP
 	else {
 		gdIOCtx *io_ctx;
 		io_ctx = gdNewDynamicCtxEx(8, data, 0);
 		if (io_ctx) {
-			if (getmbi((int(*)(void *)) gdGetC, io_ctx) == 0 && skipheader((int(*)(void *)) gdGetC, io_ctx) == 0 ) {
+			if (getmbi((int(*)(void *)) io_ctx->getC, io_ctx) == 0 && skipheader((int(*)(void *)) io_ctx->getC, io_ctx) == 0 ) {
 #if HAVE_LIBGD204
 				io_ctx->gd_free(io_ctx);
 #else
@@ -2427,7 +2425,6 @@ static int _php_image_type (char data[8])
 		}
 	}
 #endif
-#endif
 	return -1;
 #endif
 }
diff --git a/ext/gd/libgd/gd_compat.c b/ext/gd/libgd/gd_compat.c
index b56329029e..f3627a1404 100644
--- a/ext/gd/libgd/gd_compat.c
+++ b/ext/gd/libgd/gd_compat.c
@@ -33,6 +33,7 @@ const char * gdPngGetVersionString()
 }
 #endif
 
+/* Not exported by libgd, copied from gdhelpers.h */
 int overflow2(int a, int b)
 {
 	if(a <= 0 || b <= 0) {
@@ -44,3 +45,38 @@ int overflow2(int a, int b)
 	return 0;
 }
 
+/* Not exported by libgd, copied from wbmp.c */
+int
+getmbi (int (*getin) (void *in), void *in)
+{
+  int i, mbi = 0;
+
+  do
+    {
+      i = getin (in);
+      if (i < 0)
+	return (-1);
+      mbi = (mbi << 7) | (i & 0x7f);
+    }
+  while (i & 0x80);
+
+  return (mbi);
+}
+
+/* Not exported by libgd, copied from wbmp.c */
+int
+skipheader (int (*getin) (void *in), void *in)
+{
+  int i;
+
+  do
+    {
+      i = getin (in);
+      if (i < 0)
+	return (-1);
+    }
+  while (i & 0x80);
+
+  return (0);
+}
+
diff --git a/ext/gd/libgd/gd_compat.h b/ext/gd/libgd/gd_compat.h
index 779e709a63..e8fedf80c5 100644
--- a/ext/gd/libgd/gd_compat.h
+++ b/ext/gd/libgd/gd_compat.h
@@ -11,6 +11,9 @@ const char * gdPngGetVersionString();
 const char * gdJpegGetVersionString();
 int gdJpegGetVersionInt();
 int overflow2(int a, int b);
+int getmbi (int (*getin) (void *in), void *in);
+int skipheader (int (*getin) (void *in), void *in);
+
 
 /* filters section
  *