Update giflib to 5.1.1

BUG:23351000

Change-Id: I7641388fe78c5e66f4ffc178b76411dcb79f4e8a
diff --git a/egif_lib.c b/egif_lib.c
new file mode 100644
index 0000000..754d914
--- /dev/null
+++ b/egif_lib.c
@@ -0,0 +1,1152 @@
+/******************************************************************************
+
+egif_lib.c - GIF encoding
+
+The functions here and in dgif_lib.c are partitioned carefully so that
+if you only require one of read and write capability, only one of these
+two modules will be linked.  Preserve this property!
+
+*****************************************************************************/
+
+#include <unistd.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+
+#ifdef _WIN32
+#include <io.h>
+#else
+#include <sys/types.h>
+#endif /* _WIN32 */
+#include <sys/stat.h>
+
+#include "gif_lib.h"
+#include "gif_lib_private.h"
+
+/* Masks given codes to BitsPerPixel, to make sure all codes are in range: */
+/*@+charint@*/
+static const GifPixelType CodeMask[] = {
+    0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff
+};
+/*@-charint@*/
+
+static int EGifPutWord(int Word, GifFileType * GifFile);
+static int EGifSetupCompress(GifFileType * GifFile);
+static int EGifCompressLine(GifFileType * GifFile, GifPixelType * Line,
+                            int LineLen);
+static int EGifCompressOutput(GifFileType * GifFile, int Code);
+static int EGifBufferedOutput(GifFileType * GifFile, GifByteType * Buf,
+                              int c);
+
+/* extract bytes from an unsigned word */
+#define LOBYTE(x)	((x) & 0xff)
+#define HIBYTE(x)	(((x) >> 8) & 0xff)
+
+/******************************************************************************
+ Open a new GIF file for write, specified by name. If TestExistance then
+ if the file exists this routines fails (returns NULL).
+ Returns a dynamically allocated GifFileType pointer which serves as the GIF
+ info record. The Error member is cleared if successful.
+******************************************************************************/
+GifFileType *
+EGifOpenFileName(const char *FileName, const bool TestExistence, int *Error)
+{
+
+    int FileHandle;
+    GifFileType *GifFile;
+
+    if (TestExistence)
+        /* android-changed: changed "S_IREAD | S_IWRITE" to "S_IRUSR | S_IWUSR" */
+        FileHandle = open(FileName, O_WRONLY | O_CREAT | O_EXCL,
+                          S_IRUSR | S_IWUSR);
+    else
+        /* android-changed: changed "S_IREAD | S_IWRITE" to "S_IRUSR | S_IWUSR" */
+        FileHandle = open(FileName, O_WRONLY | O_CREAT | O_TRUNC,
+                          S_IRUSR | S_IWUSR);
+
+    if (FileHandle == -1) {
+        if (Error != NULL)
+	    *Error = E_GIF_ERR_OPEN_FAILED;
+        return NULL;
+    }
+    GifFile = EGifOpenFileHandle(FileHandle, Error);
+    if (GifFile == (GifFileType *) NULL)
+        (void)close(FileHandle);
+    return GifFile;
+}
+
+/******************************************************************************
+ Update a new GIF file, given its file handle, which must be opened for
+ write in binary mode.
+ Returns dynamically allocated a GifFileType pointer which serves as the GIF
+ info record.
+ Only fails on a memory allocation error.
+******************************************************************************/
+GifFileType *
+EGifOpenFileHandle(const int FileHandle, int *Error)
+{
+    GifFileType *GifFile;
+    GifFilePrivateType *Private;
+    FILE *f;
+
+    GifFile = (GifFileType *) malloc(sizeof(GifFileType));
+    if (GifFile == NULL) {
+        return NULL;
+    }
+
+    memset(GifFile, '\0', sizeof(GifFileType));
+
+    Private = (GifFilePrivateType *)malloc(sizeof(GifFilePrivateType));
+    if (Private == NULL) {
+        free(GifFile);
+        if (Error != NULL)
+	    *Error = E_GIF_ERR_NOT_ENOUGH_MEM;
+        return NULL;
+    }
+    if ((Private->HashTable = _InitHashTable()) == NULL) {
+        free(GifFile);
+        free(Private);
+        if (Error != NULL)
+	    *Error = E_GIF_ERR_NOT_ENOUGH_MEM;
+        return NULL;
+    }
+
+#ifdef _WIN32
+    _setmode(FileHandle, O_BINARY);    /* Make sure it is in binary mode. */
+#endif /* _WIN32 */
+
+    f = fdopen(FileHandle, "wb");    /* Make it into a stream: */
+
+    GifFile->Private = (void *)Private;
+    Private->FileHandle = FileHandle;
+    Private->File = f;
+    Private->FileState = FILE_STATE_WRITE;
+
+    Private->Write = (OutputFunc) 0;    /* No user write routine (MRB) */
+    GifFile->UserData = (void *)NULL;    /* No user write handle (MRB) */
+
+    GifFile->Error = 0;
+
+    return GifFile;
+}
+
+/******************************************************************************
+ Output constructor that takes user supplied output function.
+ Basically just a copy of EGifOpenFileHandle. (MRB)
+******************************************************************************/
+GifFileType *
+EGifOpen(void *userData, OutputFunc writeFunc, int *Error)
+{
+    GifFileType *GifFile;
+    GifFilePrivateType *Private;
+
+    GifFile = (GifFileType *)malloc(sizeof(GifFileType));
+    if (GifFile == NULL) {
+        if (Error != NULL)
+	    *Error = E_GIF_ERR_NOT_ENOUGH_MEM;
+        return NULL;
+    }
+
+    memset(GifFile, '\0', sizeof(GifFileType));
+
+    Private = (GifFilePrivateType *)malloc(sizeof(GifFilePrivateType));
+    if (Private == NULL) {
+        free(GifFile);
+        if (Error != NULL)
+	    *Error = E_GIF_ERR_NOT_ENOUGH_MEM;
+        return NULL;
+    }
+
+    Private->HashTable = _InitHashTable();
+    if (Private->HashTable == NULL) {
+        free (GifFile);
+        free (Private);
+        if (Error != NULL)
+	    *Error = E_GIF_ERR_NOT_ENOUGH_MEM;
+        return NULL;
+    }
+
+    GifFile->Private = (void *)Private;
+    Private->FileHandle = 0;
+    Private->File = (FILE *) 0;
+    Private->FileState = FILE_STATE_WRITE;
+
+    Private->Write = writeFunc;    /* User write routine (MRB) */
+    GifFile->UserData = userData;    /* User write handle (MRB) */
+
+    Private->gif89 = false;	/* initially, write GIF87 */
+
+    GifFile->Error = 0;
+
+    return GifFile;
+}
+
+/******************************************************************************
+ Routine to compute the GIF version that will be written on output.
+******************************************************************************/
+const char *
+EGifGetGifVersion(GifFileType *GifFile)
+{
+    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
+    int i, j;
+
+    /* 
+     * Bulletproofing - always write GIF89 if we need to.
+     * Note, we don't clear the gif89 flag here because
+     * users of the sequential API might have called EGifSetGifVersion()
+     * in order to set that flag.
+     */
+    for (i = 0; i < GifFile->ImageCount; i++) {
+        for (j = 0; j < GifFile->SavedImages[i].ExtensionBlockCount; j++) {
+            int function =
+               GifFile->SavedImages[i].ExtensionBlocks[j].Function;
+
+            if (function == COMMENT_EXT_FUNC_CODE
+                || function == GRAPHICS_EXT_FUNC_CODE
+                || function == PLAINTEXT_EXT_FUNC_CODE
+                || function == APPLICATION_EXT_FUNC_CODE)
+                Private->gif89 = true;
+        }
+    }
+    for (i = 0; i < GifFile->ExtensionBlockCount; i++) {
+	int function = GifFile->ExtensionBlocks[i].Function;
+
+	if (function == COMMENT_EXT_FUNC_CODE
+	    || function == GRAPHICS_EXT_FUNC_CODE
+	    || function == PLAINTEXT_EXT_FUNC_CODE
+	    || function == APPLICATION_EXT_FUNC_CODE)
+	    Private->gif89 = true;
+    }
+ 
+    if (Private->gif89)
+	return GIF89_STAMP;
+    else
+	return GIF87_STAMP;
+}
+
+/******************************************************************************
+ Set the GIF version. In the extremely unlikely event that there is ever
+ another version, replace the bool argument with an enum in which the 
+ GIF87 value is 0 (numerically the same as bool false) and the GIF89 value
+ is 1 (numerically the same as bool true).  That way we'll even preserve
+ object-file compatibility!
+******************************************************************************/
+void EGifSetGifVersion(GifFileType *GifFile, const bool gif89)
+{
+    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
+
+    Private->gif89 = gif89;
+}
+
+/******************************************************************************
+ All writes to the GIF should go through this.
+******************************************************************************/
+static int InternalWrite(GifFileType *GifFileOut, 
+		   const unsigned char *buf, size_t len)
+{
+    GifFilePrivateType *Private = (GifFilePrivateType*)GifFileOut->Private;
+    if (Private->Write)
+	return Private->Write(GifFileOut,buf,len);
+    else
+	return fwrite(buf, 1, len, Private->File);
+}
+
+/******************************************************************************
+ This routine should be called before any other EGif calls, immediately
+ following the GIF file opening.
+******************************************************************************/
+int
+EGifPutScreenDesc(GifFileType *GifFile,
+                  const int Width,
+                  const int Height,
+                  const int ColorRes,
+                  const int BackGround,
+                  const ColorMapObject *ColorMap)
+{
+    GifByteType Buf[3];
+    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
+    const char *write_version;
+
+    if (Private->FileState & FILE_STATE_SCREEN) {
+        /* If already has screen descriptor - something is wrong! */
+        GifFile->Error = E_GIF_ERR_HAS_SCRN_DSCR;
+        return GIF_ERROR;
+    }
+    if (!IS_WRITEABLE(Private)) {
+        /* This file was NOT open for writing: */
+        GifFile->Error = E_GIF_ERR_NOT_WRITEABLE;
+        return GIF_ERROR;
+    }
+
+    write_version = EGifGetGifVersion(GifFile);
+
+    /* First write the version prefix into the file. */
+    if (InternalWrite(GifFile, (unsigned char *)write_version,
+              strlen(write_version)) != strlen(write_version)) {
+        GifFile->Error = E_GIF_ERR_WRITE_FAILED;
+        return GIF_ERROR;
+    }
+
+    GifFile->SWidth = Width;
+    GifFile->SHeight = Height;
+    GifFile->SColorResolution = ColorRes;
+    GifFile->SBackGroundColor = BackGround;
+    if (ColorMap) {
+        GifFile->SColorMap = GifMakeMapObject(ColorMap->ColorCount,
+                                           ColorMap->Colors);
+        if (GifFile->SColorMap == NULL) {
+            GifFile->Error = E_GIF_ERR_NOT_ENOUGH_MEM;
+            return GIF_ERROR;
+        }
+    } else
+        GifFile->SColorMap = NULL;
+
+    /*
+     * Put the logical screen descriptor into the file:
+     */
+    /* Logical Screen Descriptor: Dimensions */
+    (void)EGifPutWord(Width, GifFile);
+    (void)EGifPutWord(Height, GifFile);
+
+    /* Logical Screen Descriptor: Packed Fields */
+    /* Note: We have actual size of the color table default to the largest
+     * possible size (7+1 == 8 bits) because the decoder can use it to decide
+     * how to display the files.
+     */
+    Buf[0] = (ColorMap ? 0x80 : 0x00) | /* Yes/no global colormap */
+             ((ColorRes - 1) << 4) | /* Bits allocated to each primary color */
+        (ColorMap ? ColorMap->BitsPerPixel - 1 : 0x07 ); /* Actual size of the
+                                                            color table. */
+    if (ColorMap != NULL && ColorMap->SortFlag)
+	Buf[0] |= 0x08;
+    Buf[1] = BackGround;    /* Index into the ColorTable for background color */
+    Buf[2] = GifFile->AspectByte;     /* Pixel Aspect Ratio */
+    InternalWrite(GifFile, Buf, 3);
+
+    /* If we have Global color map - dump it also: */
+    if (ColorMap != NULL) {
+	int i;
+        for (i = 0; i < ColorMap->ColorCount; i++) {
+            /* Put the ColorMap out also: */
+            Buf[0] = ColorMap->Colors[i].Red;
+            Buf[1] = ColorMap->Colors[i].Green;
+            Buf[2] = ColorMap->Colors[i].Blue;
+            if (InternalWrite(GifFile, Buf, 3) != 3) {
+                GifFile->Error = E_GIF_ERR_WRITE_FAILED;
+                return GIF_ERROR;
+            }
+        }
+    }
+
+    /* Mark this file as has screen descriptor, and no pixel written yet: */
+    Private->FileState |= FILE_STATE_SCREEN;
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ This routine should be called before any attempt to dump an image - any
+ call to any of the pixel dump routines.
+******************************************************************************/
+int
+EGifPutImageDesc(GifFileType *GifFile,
+                 const int Left,
+                 const int Top,
+                 const int Width,
+                 const int Height,
+                 const bool Interlace,
+                 const ColorMapObject *ColorMap)
+{
+    GifByteType Buf[3];
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (Private->FileState & FILE_STATE_IMAGE &&
+        Private->PixelCount > 0xffff0000UL) {
+        /* If already has active image descriptor - something is wrong! */
+        GifFile->Error = E_GIF_ERR_HAS_IMAG_DSCR;
+        return GIF_ERROR;
+    }
+    if (!IS_WRITEABLE(Private)) {
+        /* This file was NOT open for writing: */
+        GifFile->Error = E_GIF_ERR_NOT_WRITEABLE;
+        return GIF_ERROR;
+    }
+    GifFile->Image.Left = Left;
+    GifFile->Image.Top = Top;
+    GifFile->Image.Width = Width;
+    GifFile->Image.Height = Height;
+    GifFile->Image.Interlace = Interlace;
+    if (ColorMap) {
+	if (GifFile->Image.ColorMap != NULL) {
+	    GifFreeMapObject(GifFile->Image.ColorMap);
+	    GifFile->Image.ColorMap = NULL;
+	}
+        GifFile->Image.ColorMap = GifMakeMapObject(ColorMap->ColorCount,
+                                                ColorMap->Colors);
+        if (GifFile->Image.ColorMap == NULL) {
+            GifFile->Error = E_GIF_ERR_NOT_ENOUGH_MEM;
+            return GIF_ERROR;
+        }
+    } else {
+        GifFile->Image.ColorMap = NULL;
+    }
+
+    /* Put the image descriptor into the file: */
+    Buf[0] = DESCRIPTOR_INTRODUCER;    /* Image separator character. */
+    InternalWrite(GifFile, Buf, 1);
+    (void)EGifPutWord(Left, GifFile);
+    (void)EGifPutWord(Top, GifFile);
+    (void)EGifPutWord(Width, GifFile);
+    (void)EGifPutWord(Height, GifFile);
+    Buf[0] = (ColorMap ? 0x80 : 0x00) |
+       (Interlace ? 0x40 : 0x00) |
+       (ColorMap ? ColorMap->BitsPerPixel - 1 : 0);
+    InternalWrite(GifFile, Buf, 1);
+
+    /* If we have Global color map - dump it also: */
+    if (ColorMap != NULL) {
+	int i;
+        for (i = 0; i < ColorMap->ColorCount; i++) {
+            /* Put the ColorMap out also: */
+            Buf[0] = ColorMap->Colors[i].Red;
+            Buf[1] = ColorMap->Colors[i].Green;
+            Buf[2] = ColorMap->Colors[i].Blue;
+            if (InternalWrite(GifFile, Buf, 3) != 3) {
+                GifFile->Error = E_GIF_ERR_WRITE_FAILED;
+                return GIF_ERROR;
+            }
+        }
+    }
+    if (GifFile->SColorMap == NULL && GifFile->Image.ColorMap == NULL) {
+        GifFile->Error = E_GIF_ERR_NO_COLOR_MAP;
+        return GIF_ERROR;
+    }
+
+    /* Mark this file as has screen descriptor: */
+    Private->FileState |= FILE_STATE_IMAGE;
+    Private->PixelCount = (long)Width *(long)Height;
+
+    /* Reset compress algorithm parameters. */
+    (void)EGifSetupCompress(GifFile);
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ Put one full scanned line (Line) of length LineLen into GIF file.
+******************************************************************************/
+int
+EGifPutLine(GifFileType * GifFile, GifPixelType *Line, int LineLen)
+{
+    int i;
+    GifPixelType Mask;
+    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
+
+    if (!IS_WRITEABLE(Private)) {
+        /* This file was NOT open for writing: */
+        GifFile->Error = E_GIF_ERR_NOT_WRITEABLE;
+        return GIF_ERROR;
+    }
+
+    if (!LineLen)
+        LineLen = GifFile->Image.Width;
+    if (Private->PixelCount < (unsigned)LineLen) {
+        GifFile->Error = E_GIF_ERR_DATA_TOO_BIG;
+        return GIF_ERROR;
+    }
+    Private->PixelCount -= LineLen;
+
+    /* Make sure the codes are not out of bit range, as we might generate
+     * wrong code (because of overflow when we combine them) in this case: */
+    Mask = CodeMask[Private->BitsPerPixel];
+    for (i = 0; i < LineLen; i++)
+        Line[i] &= Mask;
+
+    return EGifCompressLine(GifFile, Line, LineLen);
+}
+
+/******************************************************************************
+ Put one pixel (Pixel) into GIF file.
+******************************************************************************/
+int
+EGifPutPixel(GifFileType *GifFile, GifPixelType Pixel)
+{
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (!IS_WRITEABLE(Private)) {
+        /* This file was NOT open for writing: */
+        GifFile->Error = E_GIF_ERR_NOT_WRITEABLE;
+        return GIF_ERROR;
+    }
+
+    if (Private->PixelCount == 0) {
+        GifFile->Error = E_GIF_ERR_DATA_TOO_BIG;
+        return GIF_ERROR;
+    }
+    --Private->PixelCount;
+
+    /* Make sure the code is not out of bit range, as we might generate
+     * wrong code (because of overflow when we combine them) in this case: */
+    Pixel &= CodeMask[Private->BitsPerPixel];
+
+    return EGifCompressLine(GifFile, &Pixel, 1);
+}
+
+/******************************************************************************
+ Put a comment into GIF file using the GIF89 comment extension block.
+******************************************************************************/
+int
+EGifPutComment(GifFileType *GifFile, const char *Comment)
+{
+    unsigned int length;
+    char *buf;
+
+    length = strlen(Comment);
+    if (length <= 255) {
+        return EGifPutExtension(GifFile, COMMENT_EXT_FUNC_CODE,
+                                length, Comment);
+    } else {
+        buf = (char *)Comment;
+        if (EGifPutExtensionLeader(GifFile, COMMENT_EXT_FUNC_CODE)
+                == GIF_ERROR) {
+            return GIF_ERROR;
+        }
+
+        /* Break the comment into 255 byte sub blocks */
+        while (length > 255) {
+            if (EGifPutExtensionBlock(GifFile, 255, buf) == GIF_ERROR) {
+                return GIF_ERROR;
+            }
+            buf = buf + 255;
+            length -= 255;
+        }
+        /* Output any partial block and the clear code. */
+        if (length > 0) {
+            if (EGifPutExtensionBlock(GifFile, length, buf) == GIF_ERROR) {
+                return GIF_ERROR;
+            }
+        }
+	if (EGifPutExtensionTrailer(GifFile) == GIF_ERROR) {
+	    return GIF_ERROR;
+        }
+    }
+    return GIF_OK;
+}
+
+/******************************************************************************
+ Begin an extension block (see GIF manual).  More
+ extensions can be dumped using EGifPutExtensionBlock until
+ EGifPutExtensionTrailer is invoked.
+******************************************************************************/
+int
+EGifPutExtensionLeader(GifFileType *GifFile, const int ExtCode)
+{
+    GifByteType Buf[3];
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (!IS_WRITEABLE(Private)) {
+        /* This file was NOT open for writing: */
+        GifFile->Error = E_GIF_ERR_NOT_WRITEABLE;
+        return GIF_ERROR;
+    }
+
+    Buf[0] = EXTENSION_INTRODUCER;
+    Buf[1] = ExtCode;
+    InternalWrite(GifFile, Buf, 2);
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ Put extension block data (see GIF manual) into a GIF file.
+******************************************************************************/
+int
+EGifPutExtensionBlock(GifFileType *GifFile, 
+		     const int ExtLen,
+		     const void *Extension)
+{
+    GifByteType Buf;
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (!IS_WRITEABLE(Private)) {
+        /* This file was NOT open for writing: */
+        GifFile->Error = E_GIF_ERR_NOT_WRITEABLE;
+        return GIF_ERROR;
+    }
+
+    Buf = ExtLen;
+    InternalWrite(GifFile, &Buf, 1);
+    InternalWrite(GifFile, Extension, ExtLen);
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ Put a terminating block (see GIF manual) into a GIF file.
+******************************************************************************/
+int
+EGifPutExtensionTrailer(GifFileType *GifFile) {
+
+    GifByteType Buf;
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (!IS_WRITEABLE(Private)) {
+        /* This file was NOT open for writing: */
+        GifFile->Error = E_GIF_ERR_NOT_WRITEABLE;
+        return GIF_ERROR;
+    }
+
+    /* Write the block terminator */
+    Buf = 0;
+    InternalWrite(GifFile, &Buf, 1);
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ Put an extension block (see GIF manual) into a GIF file.
+ Warning: This function is only useful for Extension blocks that have at
+ most one subblock.  Extensions with more than one subblock need to use the
+ EGifPutExtension{Leader,Block,Trailer} functions instead.
+******************************************************************************/
+int
+EGifPutExtension(GifFileType *GifFile,
+                 const int ExtCode,
+                 const int ExtLen,
+                 const void *Extension) {
+
+    GifByteType Buf[3];
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (!IS_WRITEABLE(Private)) {
+        /* This file was NOT open for writing: */
+        GifFile->Error = E_GIF_ERR_NOT_WRITEABLE;
+        return GIF_ERROR;
+    }
+
+    if (ExtCode == 0)
+        InternalWrite(GifFile, (GifByteType *)&ExtLen, 1);
+    else {
+        Buf[0] = EXTENSION_INTRODUCER;
+        Buf[1] = ExtCode;   /* Extension Label */
+        Buf[2] = ExtLen;    /* Extension length */
+        InternalWrite(GifFile, Buf, 3);
+    }
+    InternalWrite(GifFile, Extension, ExtLen);
+    Buf[0] = 0;
+    InternalWrite(GifFile, Buf, 1);
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ Render a Graphics Control Block as raw extension data
+******************************************************************************/
+
+size_t EGifGCBToExtension(const GraphicsControlBlock *GCB,
+		       GifByteType *GifExtension)
+{
+    GifExtension[0] = 0;
+    GifExtension[0] |= (GCB->TransparentColor == NO_TRANSPARENT_COLOR) ? 0x00 : 0x01;
+    GifExtension[0] |= GCB->UserInputFlag ? 0x02 : 0x00;
+    GifExtension[0] |= ((GCB->DisposalMode & 0x07) << 2);
+    GifExtension[1] = LOBYTE(GCB->DelayTime);
+    GifExtension[2] = HIBYTE(GCB->DelayTime);
+    GifExtension[3] = (char)GCB->TransparentColor;
+    return 4;
+}
+
+/******************************************************************************
+ Replace the Graphics Control Block for a saved image, if it exists.
+******************************************************************************/
+
+int EGifGCBToSavedExtension(const GraphicsControlBlock *GCB, 
+			    GifFileType *GifFile, int ImageIndex)
+{
+    int i;
+    size_t Len;
+    GifByteType buf[sizeof(GraphicsControlBlock)]; /* a bit dodgy... */
+
+    if (ImageIndex < 0 || ImageIndex > GifFile->ImageCount - 1)
+	return GIF_ERROR;
+
+    for (i = 0; i < GifFile->SavedImages[ImageIndex].ExtensionBlockCount; i++) {
+	ExtensionBlock *ep = &GifFile->SavedImages[ImageIndex].ExtensionBlocks[i];
+	if (ep->Function == GRAPHICS_EXT_FUNC_CODE) {
+	    EGifGCBToExtension(GCB, ep->Bytes);
+	    return GIF_OK;
+	}
+    }
+
+    Len = EGifGCBToExtension(GCB, (GifByteType *)buf);
+    if (GifAddExtensionBlock(&GifFile->SavedImages[ImageIndex].ExtensionBlockCount,
+			     &GifFile->SavedImages[ImageIndex].ExtensionBlocks,
+			     GRAPHICS_EXT_FUNC_CODE,
+			     Len,
+			     (unsigned char *)buf) == GIF_ERROR)
+	return (GIF_ERROR);
+
+    return (GIF_OK);
+}
+
+/******************************************************************************
+ Put the image code in compressed form. This routine can be called if the
+ information needed to be piped out as is. Obviously this is much faster
+ than decoding and encoding again. This routine should be followed by calls
+ to EGifPutCodeNext, until NULL block is given.
+ The block should NOT be freed by the user (not dynamically allocated).
+******************************************************************************/
+int
+EGifPutCode(GifFileType *GifFile, int CodeSize, const GifByteType *CodeBlock)
+{
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (!IS_WRITEABLE(Private)) {
+        /* This file was NOT open for writing: */
+        GifFile->Error = E_GIF_ERR_NOT_WRITEABLE;
+        return GIF_ERROR;
+    }
+
+    /* No need to dump code size as Compression set up does any for us: */
+    /* 
+     * Buf = CodeSize;
+     * if (InternalWrite(GifFile, &Buf, 1) != 1) {
+     *      GifFile->Error = E_GIF_ERR_WRITE_FAILED;
+     *      return GIF_ERROR;
+     * }
+     */
+
+    return EGifPutCodeNext(GifFile, CodeBlock);
+}
+
+/******************************************************************************
+ Continue to put the image code in compressed form. This routine should be
+ called with blocks of code as read via DGifGetCode/DGifGetCodeNext. If
+ given buffer pointer is NULL, empty block is written to mark end of code.
+******************************************************************************/
+int
+EGifPutCodeNext(GifFileType *GifFile, const GifByteType *CodeBlock)
+{
+    GifByteType Buf;
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (CodeBlock != NULL) {
+        if (InternalWrite(GifFile, CodeBlock, CodeBlock[0] + 1)
+               != (unsigned)(CodeBlock[0] + 1)) {
+            GifFile->Error = E_GIF_ERR_WRITE_FAILED;
+            return GIF_ERROR;
+        }
+    } else {
+        Buf = 0;
+        if (InternalWrite(GifFile, &Buf, 1) != 1) {
+            GifFile->Error = E_GIF_ERR_WRITE_FAILED;
+            return GIF_ERROR;
+        }
+        Private->PixelCount = 0;    /* And local info. indicate image read. */
+    }
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ This routine should be called last, to close the GIF file.
+******************************************************************************/
+int
+EGifCloseFile(GifFileType *GifFile, int *ErrorCode)
+{
+    GifByteType Buf;
+    GifFilePrivateType *Private;
+    FILE *File;
+
+    if (GifFile == NULL)
+        return GIF_ERROR;
+
+    Private = (GifFilePrivateType *) GifFile->Private;
+    if (Private == NULL)
+	return GIF_ERROR;
+    if (!IS_WRITEABLE(Private)) {
+        /* This file was NOT open for writing: */
+	if (ErrorCode != NULL)
+	    *ErrorCode = E_GIF_ERR_NOT_WRITEABLE;
+	free(GifFile);
+        return GIF_ERROR;
+    }
+
+    File = Private->File;
+
+    Buf = TERMINATOR_INTRODUCER;
+    InternalWrite(GifFile, &Buf, 1);
+
+    if (GifFile->Image.ColorMap) {
+        GifFreeMapObject(GifFile->Image.ColorMap);
+        GifFile->Image.ColorMap = NULL;
+    }
+    if (GifFile->SColorMap) {
+        GifFreeMapObject(GifFile->SColorMap);
+        GifFile->SColorMap = NULL;
+    }
+    if (Private) {
+        if (Private->HashTable) {
+            free((char *) Private->HashTable);
+        }
+	free((char *) Private);
+    }
+
+    if (File && fclose(File) != 0) {
+	if (ErrorCode != NULL)
+	    *ErrorCode = E_GIF_ERR_CLOSE_FAILED;
+	free(GifFile);
+        return GIF_ERROR;
+    }
+
+    free(GifFile);
+    if (ErrorCode != NULL)
+	*ErrorCode = E_GIF_SUCCEEDED;
+    return GIF_OK;
+}
+
+/******************************************************************************
+ Put 2 bytes (a word) into the given file in little-endian order:
+******************************************************************************/
+static int
+EGifPutWord(int Word, GifFileType *GifFile)
+{
+    unsigned char c[2];
+
+    c[0] = LOBYTE(Word);
+    c[1] = HIBYTE(Word);
+    if (InternalWrite(GifFile, c, 2) == 2)
+        return GIF_OK;
+    else
+        return GIF_ERROR;
+}
+
+/******************************************************************************
+ Setup the LZ compression for this image:
+******************************************************************************/
+static int
+EGifSetupCompress(GifFileType *GifFile)
+{
+    int BitsPerPixel;
+    GifByteType Buf;
+    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
+
+    /* Test and see what color map to use, and from it # bits per pixel: */
+    if (GifFile->Image.ColorMap)
+        BitsPerPixel = GifFile->Image.ColorMap->BitsPerPixel;
+    else if (GifFile->SColorMap)
+        BitsPerPixel = GifFile->SColorMap->BitsPerPixel;
+    else {
+        GifFile->Error = E_GIF_ERR_NO_COLOR_MAP;
+        return GIF_ERROR;
+    }
+
+    Buf = BitsPerPixel = (BitsPerPixel < 2 ? 2 : BitsPerPixel);
+    InternalWrite(GifFile, &Buf, 1);    /* Write the Code size to file. */
+
+    Private->Buf[0] = 0;    /* Nothing was output yet. */
+    Private->BitsPerPixel = BitsPerPixel;
+    Private->ClearCode = (1 << BitsPerPixel);
+    Private->EOFCode = Private->ClearCode + 1;
+    Private->RunningCode = Private->EOFCode + 1;
+    Private->RunningBits = BitsPerPixel + 1;    /* Number of bits per code. */
+    Private->MaxCode1 = 1 << Private->RunningBits;    /* Max. code + 1. */
+    Private->CrntCode = FIRST_CODE;    /* Signal that this is first one! */
+    Private->CrntShiftState = 0;    /* No information in CrntShiftDWord. */
+    Private->CrntShiftDWord = 0;
+
+   /* Clear hash table and send Clear to make sure the decoder do the same. */
+    _ClearHashTable(Private->HashTable);
+
+    if (EGifCompressOutput(GifFile, Private->ClearCode) == GIF_ERROR) {
+        GifFile->Error = E_GIF_ERR_DISK_IS_FULL;
+        return GIF_ERROR;
+    }
+    return GIF_OK;
+}
+
+/******************************************************************************
+ The LZ compression routine:
+ This version compresses the given buffer Line of length LineLen.
+ This routine can be called a few times (one per scan line, for example), in
+ order to complete the whole image.
+******************************************************************************/
+static int
+EGifCompressLine(GifFileType *GifFile,
+                 GifPixelType *Line,
+                 const int LineLen)
+{
+    int i = 0, CrntCode, NewCode;
+    unsigned long NewKey;
+    GifPixelType Pixel;
+    GifHashTableType *HashTable;
+    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
+
+    HashTable = Private->HashTable;
+
+    if (Private->CrntCode == FIRST_CODE)    /* Its first time! */
+        CrntCode = Line[i++];
+    else
+        CrntCode = Private->CrntCode;    /* Get last code in compression. */
+
+    while (i < LineLen) {   /* Decode LineLen items. */
+        Pixel = Line[i++];  /* Get next pixel from stream. */
+        /* Form a new unique key to search hash table for the code combines 
+         * CrntCode as Prefix string with Pixel as postfix char.
+         */
+        NewKey = (((uint32_t) CrntCode) << 8) + Pixel;
+        if ((NewCode = _ExistsHashTable(HashTable, NewKey)) >= 0) {
+            /* This Key is already there, or the string is old one, so
+             * simple take new code as our CrntCode:
+             */
+            CrntCode = NewCode;
+        } else {
+            /* Put it in hash table, output the prefix code, and make our
+             * CrntCode equal to Pixel.
+             */
+            if (EGifCompressOutput(GifFile, CrntCode) == GIF_ERROR) {
+                GifFile->Error = E_GIF_ERR_DISK_IS_FULL;
+                return GIF_ERROR;
+            }
+            CrntCode = Pixel;
+
+            /* If however the HashTable if full, we send a clear first and
+             * Clear the hash table.
+             */
+            if (Private->RunningCode >= LZ_MAX_CODE) {
+                /* Time to do some clearance: */
+                if (EGifCompressOutput(GifFile, Private->ClearCode)
+                        == GIF_ERROR) {
+                    GifFile->Error = E_GIF_ERR_DISK_IS_FULL;
+                    return GIF_ERROR;
+                }
+                Private->RunningCode = Private->EOFCode + 1;
+                Private->RunningBits = Private->BitsPerPixel + 1;
+                Private->MaxCode1 = 1 << Private->RunningBits;
+                _ClearHashTable(HashTable);
+            } else {
+                /* Put this unique key with its relative Code in hash table: */
+                _InsertHashTable(HashTable, NewKey, Private->RunningCode++);
+            }
+        }
+
+    }
+
+    /* Preserve the current state of the compression algorithm: */
+    Private->CrntCode = CrntCode;
+
+    if (Private->PixelCount == 0) {
+        /* We are done - output last Code and flush output buffers: */
+        if (EGifCompressOutput(GifFile, CrntCode) == GIF_ERROR) {
+            GifFile->Error = E_GIF_ERR_DISK_IS_FULL;
+            return GIF_ERROR;
+        }
+        if (EGifCompressOutput(GifFile, Private->EOFCode) == GIF_ERROR) {
+            GifFile->Error = E_GIF_ERR_DISK_IS_FULL;
+            return GIF_ERROR;
+        }
+        if (EGifCompressOutput(GifFile, FLUSH_OUTPUT) == GIF_ERROR) {
+            GifFile->Error = E_GIF_ERR_DISK_IS_FULL;
+            return GIF_ERROR;
+        }
+    }
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ The LZ compression output routine:
+ This routine is responsible for the compression of the bit stream into
+ 8 bits (bytes) packets.
+ Returns GIF_OK if written successfully.
+******************************************************************************/
+static int
+EGifCompressOutput(GifFileType *GifFile,
+                   const int Code)
+{
+    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
+    int retval = GIF_OK;
+
+    if (Code == FLUSH_OUTPUT) {
+        while (Private->CrntShiftState > 0) {
+            /* Get Rid of what is left in DWord, and flush it. */
+            if (EGifBufferedOutput(GifFile, Private->Buf,
+                                 Private->CrntShiftDWord & 0xff) == GIF_ERROR)
+                retval = GIF_ERROR;
+            Private->CrntShiftDWord >>= 8;
+            Private->CrntShiftState -= 8;
+        }
+        Private->CrntShiftState = 0;    /* For next time. */
+        if (EGifBufferedOutput(GifFile, Private->Buf,
+                               FLUSH_OUTPUT) == GIF_ERROR)
+            retval = GIF_ERROR;
+    } else {
+        Private->CrntShiftDWord |= ((long)Code) << Private->CrntShiftState;
+        Private->CrntShiftState += Private->RunningBits;
+        while (Private->CrntShiftState >= 8) {
+            /* Dump out full bytes: */
+            if (EGifBufferedOutput(GifFile, Private->Buf,
+                                 Private->CrntShiftDWord & 0xff) == GIF_ERROR)
+                retval = GIF_ERROR;
+            Private->CrntShiftDWord >>= 8;
+            Private->CrntShiftState -= 8;
+        }
+    }
+
+    /* If code cannt fit into RunningBits bits, must raise its size. Note */
+    /* however that codes above 4095 are used for special signaling.      */
+    if (Private->RunningCode >= Private->MaxCode1 && Code <= 4095) {
+       Private->MaxCode1 = 1 << ++Private->RunningBits;
+    }
+
+    return retval;
+}
+
+/******************************************************************************
+ This routines buffers the given characters until 255 characters are ready
+ to be output. If Code is equal to -1 the buffer is flushed (EOF).
+ The buffer is Dumped with first byte as its size, as GIF format requires.
+ Returns GIF_OK if written successfully.
+******************************************************************************/
+static int
+EGifBufferedOutput(GifFileType *GifFile,
+                   GifByteType *Buf,
+                   int c)
+{
+    if (c == FLUSH_OUTPUT) {
+        /* Flush everything out. */
+        if (Buf[0] != 0
+            && InternalWrite(GifFile, Buf, Buf[0] + 1) != (unsigned)(Buf[0] + 1)) {
+            GifFile->Error = E_GIF_ERR_WRITE_FAILED;
+            return GIF_ERROR;
+        }
+        /* Mark end of compressed data, by an empty block (see GIF doc): */
+        Buf[0] = 0;
+        if (InternalWrite(GifFile, Buf, 1) != 1) {
+            GifFile->Error = E_GIF_ERR_WRITE_FAILED;
+            return GIF_ERROR;
+        }
+    } else {
+        if (Buf[0] == 255) {
+            /* Dump out this buffer - it is full: */
+            if (InternalWrite(GifFile, Buf, Buf[0] + 1) != (unsigned)(Buf[0] + 1)) {
+                GifFile->Error = E_GIF_ERR_WRITE_FAILED;
+                return GIF_ERROR;
+            }
+            Buf[0] = 0;
+        }
+        Buf[++Buf[0]] = c;
+    }
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ This routine writes to disk an in-core representation of a GIF previously
+ created by DGifSlurp().
+******************************************************************************/
+
+static int
+EGifWriteExtensions(GifFileType *GifFileOut, 
+			       ExtensionBlock *ExtensionBlocks, 
+			       int ExtensionBlockCount) 
+{
+    if (ExtensionBlocks) {
+        ExtensionBlock *ep;
+	int j;
+
+	for (j = 0; j < ExtensionBlockCount; j++) {
+	    ep = &ExtensionBlocks[j];
+	    if (ep->Function != CONTINUE_EXT_FUNC_CODE)
+		if (EGifPutExtensionLeader(GifFileOut, ep->Function) == GIF_ERROR)
+		    return (GIF_ERROR);
+	    if (EGifPutExtensionBlock(GifFileOut, ep->ByteCount, ep->Bytes) == GIF_ERROR)
+		return (GIF_ERROR);
+	    if (j == ExtensionBlockCount - 1 || (ep+1)->Function != CONTINUE_EXT_FUNC_CODE)
+		if (EGifPutExtensionTrailer(GifFileOut) == GIF_ERROR)
+		    return (GIF_ERROR);
+	}
+    }
+
+    return (GIF_OK);
+}
+
+int
+EGifSpew(GifFileType *GifFileOut) 
+{
+    int i, j; 
+
+    if (EGifPutScreenDesc(GifFileOut,
+                          GifFileOut->SWidth,
+                          GifFileOut->SHeight,
+                          GifFileOut->SColorResolution,
+                          GifFileOut->SBackGroundColor,
+                          GifFileOut->SColorMap) == GIF_ERROR) {
+        return (GIF_ERROR);
+    }
+
+    for (i = 0; i < GifFileOut->ImageCount; i++) {
+        SavedImage *sp = &GifFileOut->SavedImages[i];
+        int SavedHeight = sp->ImageDesc.Height;
+        int SavedWidth = sp->ImageDesc.Width;
+
+        /* this allows us to delete images by nuking their rasters */
+        if (sp->RasterBits == NULL)
+            continue;
+
+	if (EGifWriteExtensions(GifFileOut, 
+				sp->ExtensionBlocks,
+				sp->ExtensionBlockCount) == GIF_ERROR)
+	    return (GIF_ERROR);
+
+        if (EGifPutImageDesc(GifFileOut,
+                             sp->ImageDesc.Left,
+                             sp->ImageDesc.Top,
+                             SavedWidth,
+                             SavedHeight,
+                             sp->ImageDesc.Interlace,
+                             sp->ImageDesc.ColorMap) == GIF_ERROR)
+            return (GIF_ERROR);
+
+	if (sp->ImageDesc.Interlace) {
+	     /* 
+	      * The way an interlaced image should be written - 
+	      * offsets and jumps...
+	      */
+	    int InterlacedOffset[] = { 0, 4, 2, 1 };
+	    int InterlacedJumps[] = { 8, 8, 4, 2 };
+	    int k;
+	    /* Need to perform 4 passes on the images: */
+	    for (k = 0; k < 4; k++)
+		for (j = InterlacedOffset[k]; 
+		     j < SavedHeight;
+		     j += InterlacedJumps[k]) {
+		    if (EGifPutLine(GifFileOut, 
+				    sp->RasterBits + j * SavedWidth, 
+				    SavedWidth)	== GIF_ERROR)
+			return (GIF_ERROR);
+		}
+	} else {
+	    for (j = 0; j < SavedHeight; j++) {
+		if (EGifPutLine(GifFileOut,
+				sp->RasterBits + j * SavedWidth,
+				SavedWidth) == GIF_ERROR)
+		    return (GIF_ERROR);
+	    }
+	}
+    }
+
+    if (EGifWriteExtensions(GifFileOut,
+			    GifFileOut->ExtensionBlocks,
+			    GifFileOut->ExtensionBlockCount) == GIF_ERROR)
+	return (GIF_ERROR);
+
+    if (EGifCloseFile(GifFileOut, NULL) == GIF_ERROR)
+        return (GIF_ERROR);
+
+    return (GIF_OK);
+}
+
+/* end */