diff --git a/third_party/libtiff/tif_dir.c b/third_party/libtiff/tif_dir.c
index 4b3632ab1..81b849374 100644
--- a/third_party/libtiff/tif_dir.c
+++ b/third_party/libtiff/tif_dir.c
@@ -862,6 +862,32 @@ _TIFFVGetField(TIFF* tif, uint32 tag, va_list ap)
        if( fip == NULL ) /* cannot happen since TIFFGetField() already checks it */
            return 0;
        
+       if( tag == TIFFTAG_NUMBEROFINKS )
+       {
+               int i;
+               for (i = 0; i < td->td_customValueCount; i++) {
+                       uint16 val;
+                       TIFFTagValue *tv = td->td_customValues + i;
+                       if (tv->info->field_tag != tag)
+                               continue;
+                       val = *(uint16 *)tv->value;
+                       /* Truncate to SamplesPerPixel, since the */
+                       /* setting code for INKNAMES assume that there are SamplesPerPixel */
+                       /* inknames. */
+                       /* Fixes http://bugzilla.maptools.org/show_bug.cgi?id=2599 */
+                       if( val > td->td_samplesperpixel )
+                       {
+                               TIFFWarningExt(tif->tif_clientdata,"_TIFFVGetField",
+                                                          "Truncating NumberOfInks from %u to %u",
+                                                          val, td->td_samplesperpixel);
+                               val = td->td_samplesperpixel;
+                       }
+                       *va_arg(ap, uint16*) = val;
+                       return 1;
+               }
+               return 0;
+       }
+
        /*
         * We want to force the custom code to be used for custom
         * fields even if the tag happens to match a well known 
diff --git a/third_party/libtiff/tif_dirread.c b/third_party/libtiff/tif_dirread.c
index d50b39a80..7dbcf6d86 100644
--- a/third_party/libtiff/tif_dirread.c
+++ b/third_party/libtiff/tif_dirread.c
@@ -5503,8 +5503,7 @@ ChopUpSingleUncompressedStrip(TIFF* tif)
        uint64 rowblockbytes;
        uint64 stripbytes;
        uint32 strip;
-       uint64 nstrips64;
-       uint32 nstrips32;
+       uint32 nstrips;
        uint32 rowsperstrip;
        uint64* newcounts;
        uint64* newoffsets;
@@ -5535,18 +5534,17 @@ ChopUpSingleUncompressedStrip(TIFF* tif)
            return;
 
        /*
-        * never increase the number of strips in an image
+        * never increase the number of rows per strip
         */
        if (rowsperstrip >= td->td_rowsperstrip)
                return;
-       nstrips64 = TIFFhowmany_64(bytecount, stripbytes);
-       if ((nstrips64==0)||(nstrips64>0xFFFFFFFF)) /* something is wonky, do nothing. */
-           return;
-       nstrips32 = (uint32)nstrips64;
+       nstrips = TIFFhowmany_32(td->td_imagelength, rowsperstrip);
+       if( nstrips == 0 )
+               return;
 
-       newcounts = (uint64*) _TIFFCheckMalloc(tif, nstrips32, sizeof (uint64),
+       newcounts = (uint64*) _TIFFCheckMalloc(tif, nstrips, sizeof (uint64),
                                "for chopped \"StripByteCounts\" array");
-       newoffsets = (uint64*) _TIFFCheckMalloc(tif, nstrips32, sizeof (uint64),
+       newoffsets = (uint64*) _TIFFCheckMalloc(tif, nstrips, sizeof (uint64),
                                "for chopped \"StripOffsets\" array");
        if (newcounts == NULL || newoffsets == NULL) {
                /*
@@ -5563,18 +5561,18 @@ ChopUpSingleUncompressedStrip(TIFF* tif)
         * Fill the strip information arrays with new bytecounts and offsets
         * that reflect the broken-up format.
         */
-       for (strip = 0; strip < nstrips32; strip++) {
+       for (strip = 0; strip < nstrips; strip++) {
                if (stripbytes > bytecount)
                        stripbytes = bytecount;
                newcounts[strip] = stripbytes;
-               newoffsets[strip] = offset;
+               newoffsets[strip] = stripbytes ? offset : 0;
                offset += stripbytes;
                bytecount -= stripbytes;
        }
        /*
         * Replace old single strip info with multi-strip info.
         */
-       td->td_stripsperimage = td->td_nstrips = nstrips32;
+       td->td_stripsperimage = td->td_nstrips = nstrips;
        TIFFSetField(tif, TIFFTAG_ROWSPERSTRIP, rowsperstrip);
 
        _TIFFfree(td->td_stripbytecount);
diff --git a/third_party/libtiff/tif_luv.c b/third_party/libtiff/tif_luv.c
index ca08f30a7..220c15034 100644
--- a/third_party/libtiff/tif_luv.c
+++ b/third_party/libtiff/tif_luv.c
@@ -158,6 +158,7 @@
 typedef struct logLuvState LogLuvState;
 
 struct logLuvState {
+       int                     encoder_state;  /* 1 if encoder correctly initialized */
        int                     user_datafmt;   /* user data format */
        int                     encode_meth;    /* encoding method */
        int                     pixel_size;     /* bytes per pixel */
@@ -1552,6 +1553,7 @@ LogLuvSetupEncode(TIFF* tif)
                    td->td_photometric, "must be either LogLUV or LogL");
                break;
        }
+       sp->encoder_state = 1;
        return (1);
 notsupported:
        TIFFErrorExt(tif->tif_clientdata, module,
@@ -1563,19 +1565,27 @@ notsupported:
 static void
 LogLuvClose(TIFF* tif)
 {
+       LogLuvState* sp = (LogLuvState*) tif->tif_data;
        TIFFDirectory *td = &tif->tif_dir;
 
+       assert(sp != 0);
        /*
         * For consistency, we always want to write out the same
         * bitspersample and sampleformat for our TIFF file,
         * regardless of the data format being used by the application.
         * Since this routine is called after tags have been set but
         * before they have been recorded in the file, we reset them here.
+        * Note: this is really a nasty approach. See PixarLogClose
         */
-       td->td_samplesperpixel =
-           (td->td_photometric == PHOTOMETRIC_LOGL) ? 1 : 3;
-       td->td_bitspersample = 16;
-       td->td_sampleformat = SAMPLEFORMAT_INT;
+       if( sp->encoder_state )
+       {
+               /* See PixarLogClose. Might avoid issues with tags whose size depends
+                * on those below, but not completely sure this is enough. */
+               td->td_samplesperpixel =
+                       (td->td_photometric == PHOTOMETRIC_LOGL) ? 1 : 3;
+               td->td_bitspersample = 16;
+               td->td_sampleformat = SAMPLEFORMAT_INT;
+       }
 }
 
 static void
diff --git a/third_party/libtiff/tif_ojpeg.c b/third_party/libtiff/tif_ojpeg.c
index e128887bf..cb84be96b 100644
--- a/third_party/libtiff/tif_ojpeg.c
+++ b/third_party/libtiff/tif_ojpeg.c
@@ -253,6 +253,7 @@ typedef enum {
 
 typedef struct {
        TIFF* tif;
+       int decoder_ok;
        #ifndef LIBJPEG_ENCAP_EXTERNAL
        JMP_BUF exit_jmpbuf;
        #endif
@@ -731,6 +732,7 @@ OJPEGPreDecode(TIFF* tif, uint16 s)
                }
                sp->write_curstrile++;
        }
+       sp->decoder_ok = 1;
        return(1);
 }
 
@@ -793,8 +795,14 @@ OJPEGPreDecodeSkipScanlines(TIFF* tif)
 static int
 OJPEGDecode(TIFF* tif, uint8* buf, tmsize_t cc, uint16 s)
 {
+       static const char module[]="OJPEGDecode";
        OJPEGState* sp=(OJPEGState*)tif->tif_data;
        (void)s;
+       if( !sp->decoder_ok )
+       {
+               TIFFErrorExt(tif->tif_clientdata,module,"Cannot decode: decoder not correctly initialized");
+               return 0;
+       }
        if (sp->libjpeg_jpeg_query_style==0)
        {
                if (OJPEGDecodeRaw(tif,buf,cc)==0)
diff --git a/third_party/libtiff/tif_pixarlog.c b/third_party/libtiff/tif_pixarlog.c
index 8f6ca8f63..e6574ec3d 100644
--- a/third_party/libtiff/tif_pixarlog.c
+++ b/third_party/libtiff/tif_pixarlog.c
@@ -1233,8 +1233,10 @@ PixarLogPostEncode(TIFF* tif)
 static void
 PixarLogClose(TIFF* tif)
 {
+       PixarLogState* sp = (PixarLogState*) tif->tif_data;
        TIFFDirectory *td = &tif->tif_dir;
 
+       assert(sp != 0);
        /* In a really sneaky (and really incorrect, and untruthful, and
         * troublesome, and error-prone) maneuver that completely goes against
         * the spirit of TIFF, and breaks TIFF, on close, we covertly
@@ -1243,8 +1245,19 @@ PixarLogClose(TIFF* tif)
         * readers that don't know about PixarLog, or how to set
         * the PIXARLOGDATFMT pseudo-tag.
         */
-       td->td_bitspersample = 8;
-       td->td_sampleformat = SAMPLEFORMAT_UINT;
+
+       if (sp->state&PLSTATE_INIT) {
+               /* We test the state to avoid an issue such as in
+                * http://bugzilla.maptools.org/show_bug.cgi?id=2604
+                * What appends in that case is that the bitspersample is 1 and
+                * a TransferFunction is set. The size of the TransferFunction
+                * depends on 1<<bitspersample. So if we increase it, an access
+                * out of the buffer will happen at directory flushing.
+                * Another option would be to clear those targs. 
+                */
+               td->td_bitspersample = 8;
+               td->td_sampleformat = SAMPLEFORMAT_UINT;
+       }
 }
 
 static void
diff --git a/third_party/libtiff/tif_read.c b/third_party/libtiff/tif_read.c
index 795153bbf..1ba100e54 100644
--- a/third_party/libtiff/tif_read.c
+++ b/third_party/libtiff/tif_read.c
@@ -346,7 +346,7 @@ TIFFReadEncodedStrip(TIFF* tif, uint32 strip, void* buf, tmsize_t size)
        rowsperstrip=td->td_rowsperstrip;
        if (rowsperstrip>td->td_imagelength)
                rowsperstrip=td->td_imagelength;
-       stripsperplane=((td->td_imagelength+rowsperstrip-1)/rowsperstrip);
+       stripsperplane= TIFFhowmany_32_maxuint_compat(td->td_imagelength, rowsperstrip);
        stripinplane=(strip%stripsperplane);
        plane=(uint16)(strip/stripsperplane);
        rows=td->td_imagelength-stripinplane*rowsperstrip;
diff --git a/third_party/libtiff/tif_strip.c b/third_party/libtiff/tif_strip.c
index b6098dd31..3b55285cd 100644
--- a/third_party/libtiff/tif_strip.c
+++ b/third_party/libtiff/tif_strip.c
@@ -63,15 +63,6 @@ TIFFNumberOfStrips(TIFF* tif)
        TIFFDirectory *td = &tif->tif_dir;
        uint32 nstrips;
 
-    /* If the value was already computed and store in td_nstrips, then return it,
-       since ChopUpSingleUncompressedStrip might have altered and resized the
-       since the td_stripbytecount and td_stripoffset arrays to the new value
-       after the initial affectation of td_nstrips = TIFFNumberOfStrips() in
-       tif_dirread.c ~line 3612.
-       See http://bugzilla.maptools.org/show_bug.cgi?id=2587 */
-    if( td->td_nstrips )
-        return td->td_nstrips;
-
        nstrips = (td->td_rowsperstrip == (uint32) -1 ? 1 :
             TIFFhowmany_32(td->td_imagelength, td->td_rowsperstrip));
        if (td->td_planarconfig == PLANARCONFIG_SEPARATE)
diff --git a/third_party/libtiff/tiffiop.h b/third_party/libtiff/tiffiop.h
index b6db1e932..1925a6b5e 100644
--- a/third_party/libtiff/tiffiop.h
+++ b/third_party/libtiff/tiffiop.h
@@ -249,6 +249,10 @@ struct tiff {
 #define TIFFhowmany_32(x, y) (((uint32)x < (0xffffffff - (uint32)(y-1))) ? \
                           ((((uint32)(x))+(((uint32)(y))-1))/((uint32)(y))) : \
                           0U)
+/* Variant of TIFFhowmany_32() that doesn't return 0 if x close to MAXUINT. */
+/* Caution: TIFFhowmany_32_maxuint_compat(x,y)*y might overflow */
+#define TIFFhowmany_32_maxuint_compat(x, y) \
+                          (((uint32)(x) / (uint32)(y)) + ((((uint32)(x) % (uint32)(y)) != 0) ? 1 : 0))
 #define TIFFhowmany8_32(x) (((x)&0x07)?((uint32)(x)>>3)+1:(uint32)(x)>>3)
 #define TIFFroundup_32(x, y) (TIFFhowmany_32(x,y)*(y))
 #define TIFFhowmany_64(x, y) ((((uint64)(x))+(((uint64)(y))-1))/((uint64)(y)))