From c8471bcbda68b7d7bd4542bce1da9c21e1aec07d Mon Sep 17 00:00:00 2001
From: homm <homm86@gmail.com>
Date: Sat, 25 Oct 2014 05:03:27 +0400
Subject: [PATCH] Hide stretch implementation detail in Antialias.c

---
 _imaging.c             | 25 ++-----------------------
 libImaging/Antialias.c | 41 +++++++++++++++++++++++++++++++++++++----
 2 files changed, 39 insertions(+), 27 deletions(-)

diff --git a/_imaging.c b/_imaging.c
index 4eb878cf7..6cddd913b 100644
--- a/_imaging.c
+++ b/_imaging.c
@@ -1613,7 +1613,6 @@ static PyObject*
 _stretch(ImagingObject* self, PyObject* args)
 {
     Imaging imIn;
-    Imaging imTemp;
     Imaging imOut;
 
     int xsize, ysize;
@@ -1623,35 +1622,15 @@ _stretch(ImagingObject* self, PyObject* args)
 
     imIn = self->image;
 
-    /* two-pass resize: minimize size of intermediate image */
-    if ((Py_ssize_t) imIn->xsize * ysize < (Py_ssize_t) xsize * imIn->ysize)
-        imTemp = ImagingNew(imIn->mode, imIn->xsize, ysize);
-    else
-        imTemp = ImagingNew(imIn->mode, xsize, imIn->ysize);
-    if (!imTemp)
-        return NULL;
-
-    /* first pass */
-    if (!ImagingStretch(imTemp, imIn, filter)) {
-        ImagingDelete(imTemp);
-        return NULL;
-    }
-
     imOut = ImagingNew(imIn->mode, xsize, ysize);
-    if (!imOut) {
-        ImagingDelete(imTemp);
+    if ( ! imOut)
         return NULL;
-    }
 
-    /* second pass */
-    if (!ImagingStretch(imOut, imTemp, filter)) {
+    if (!ImagingStretch(imOut, imIn, filter)) {
         ImagingDelete(imOut);
-        ImagingDelete(imTemp);
         return NULL;
     }
 
-    ImagingDelete(imTemp);
-
     return PyImagingNew(imOut);
 }
 
diff --git a/libImaging/Antialias.c b/libImaging/Antialias.c
index be49bc827..fc084e952 100644
--- a/libImaging/Antialias.c
+++ b/libImaging/Antialias.c
@@ -79,7 +79,7 @@ static inline float bicubic_filter(float x)
 static struct filter BICUBIC = { bicubic_filter, 2.0 };
 
 Imaging
-ImagingStretch(Imaging imOut, Imaging imIn, int filter)
+ImagingStretchPass(Imaging imOut, Imaging imIn, int filter)
 {
     /* FIXME: this is a quick and straightforward translation from a
        python prototype.  might need some further C-ification... */
@@ -95,9 +95,6 @@ ImagingStretch(Imaging imOut, Imaging imIn, int filter)
     if (!imOut || !imIn || strcmp(imIn->mode, imOut->mode) != 0)
         return (Imaging) ImagingError_ModeError();
 
-    if (strcmp(imIn->mode, "P") == 0 || strcmp(imIn->mode, "1") == 0)
-        return (Imaging) ImagingError_ModeError();
-
     /* check filter */
     switch (filter) {
     case IMAGING_TRANSFORM_NEAREST:
@@ -305,3 +302,39 @@ ImagingStretch(Imaging imOut, Imaging imIn, int filter)
 
     return imOut;
 }
+
+
+Imaging
+ImagingStretch(Imaging imOut, Imaging imIn, int filter)
+{
+    Imaging imTemp;
+    int xsize = imOut->xsize;
+    int ysize = imOut->ysize;
+
+    if (strcmp(imIn->mode, "P") == 0 || strcmp(imIn->mode, "1") == 0)
+        return (Imaging) ImagingError_ModeError();
+
+    /* two-pass resize: minimize size of intermediate image */
+    if ((Py_ssize_t) imIn->xsize * ysize < (Py_ssize_t) xsize * imIn->ysize)
+        imTemp = ImagingNew(imIn->mode, imIn->xsize, ysize);
+    else
+        imTemp = ImagingNew(imIn->mode, xsize, imIn->ysize);
+    if ( ! imTemp)
+        return NULL;
+
+    /* first pass */
+    if ( ! ImagingStretchPass(imTemp, imIn, filter)) {
+        ImagingDelete(imTemp);
+        return NULL;
+    }
+
+    /* second pass */
+    if ( ! ImagingStretchPass(imOut, imTemp, filter)) {
+        ImagingDelete(imTemp);
+        return NULL;
+    }
+
+    ImagingDelete(imTemp);
+
+    return imOut;
+}