diff --git a/panda/src/linmath/lmatrix4.I b/panda/src/linmath/lmatrix4.I
index d2c2de645c..3148355a07 100644
--- a/panda/src/linmath/lmatrix4.I
+++ b/panda/src/linmath/lmatrix4.I
@@ -1026,9 +1026,10 @@ rotate_mat(NumType angle, LVecBase3<NumType> axis,
   }
 
   // Normalize the axis.
-  NumType length = axis.dot(axis);
-  nassertr(length != 0.0, ident_mat());
-  axis /= length;
+  NumType length2 = axis.dot(axis);
+  // Cannot rotate about a zero-length axis.
+  nassertr(length2 != 0.0, ident_mat());
+  axis /= csqrt(length2);
     
   double s = sin(deg_2_rad(angle));
   double c = cos(deg_2_rad(angle));
diff --git a/panda/src/pnmimage/pnmFileType.cxx b/panda/src/pnmimage/pnmFileType.cxx
index b1a9623aaf..5871956856 100644
--- a/panda/src/pnmimage/pnmFileType.cxx
+++ b/panda/src/pnmimage/pnmFileType.cxx
@@ -144,10 +144,10 @@ init_pnm() {
 
     pm_init(&argc, argv);
 
-    // Now deallocate all the stuff we just allocated.
-    for (i = 0; i < argc; i++) {
-      delete[] argv[i];
-    }
+    // We can delete the argv array itself, but we cannot free the
+    // results of the strdup() calls we just made, since the pnm
+    // library might keep pointers to it.  But this is a one-time
+    // leak.
     delete[] argv;
   }
 }
diff --git a/panda/src/pnmimagetypes/color.c b/panda/src/pnmimagetypes/color.c
index 3949af53bc..0e2e42d596 100644
--- a/panda/src/pnmimagetypes/color.c
+++ b/panda/src/pnmimagetypes/color.c
@@ -1,9 +1,5 @@
 /* Copyright (c) 1991 Regents of the University of California */
 
-#ifndef lint
-static char SCCSid[] = "@(#)color.c 2.8 3/26/94 LBL";
-#endif
-
 /*
  *  color.c - routines for color calculations.
  *
@@ -48,13 +44,13 @@ tempbuffer(unsigned len)		/* get a temporary buffer */
 }
 
 
-fwritecolrs(register COLR *scanline, unsigned len, register FILE *fp)
+int fwritecolrs(register COLR *scanline, unsigned len, register FILE *fp)
 		/* write out a colr scanline */
 {
 	register int  i, j, beg, cnt;
 	int  c2;
 	
-	if (len < MINELEN | len > MAXELEN)	/* OOBs, write out flat */
+	if (len < MINELEN || len > MAXELEN)	/* OOBs, write out flat */
 		return(fwrite((char *)scanline,sizeof(COLR),len,fp) - len);
 					/* put magic header */
 	putc(2, fp);
@@ -99,13 +95,13 @@ fwritecolrs(register COLR *scanline, unsigned len, register FILE *fp)
 
 int oldreadcolrs(register COLR *scanline, int len, register FILE *fp);
 
-freadcolrs(register COLR *scanline, int len, register FILE *fp)
+int freadcolrs(register COLR *scanline, int len, register FILE *fp)
 		/* read in an encoded colr scanline */
 {
 	register int  i, j;
 	int  code, val;
 					/* determine scanline type */
-	if (len < MINELEN | len > MAXELEN)
+	if (len < MINELEN || len > MAXELEN)
 		return(oldreadcolrs(scanline, len, fp));
 	if ((i = getc(fp)) == EOF)
 		return(-1);
@@ -177,7 +173,7 @@ int oldreadcolrs(register COLR *scanline, int len, register FILE *fp)
 
 
 	/* write out a scanline */
-fwritescan(register COLOR *scanline, int len, FILE *fp)	
+int fwritescan(register COLOR *scanline, int len, FILE *fp)	
 {
 	COLR  *clrscan;
 	int  n;
@@ -199,7 +195,7 @@ fwritescan(register COLOR *scanline, int len, FILE *fp)
 }
 
 
-freadscan(register COLOR *scanline, int len, FILE *fp)
+int freadscan(register COLOR *scanline, int len, FILE *fp)
 			/* read in a scanline */
 {
 	register COLR  *clrscan;
diff --git a/panda/src/pnmimagetypes/colrops.c b/panda/src/pnmimagetypes/colrops.c
index 2a0d88d7b8..6d4e0fd145 100644
--- a/panda/src/pnmimagetypes/colrops.c
+++ b/panda/src/pnmimagetypes/colrops.c
@@ -1,9 +1,5 @@
 /* Copyright (c) 1992 Regents of the University of California */
 
-#ifndef lint
-static char SCCSid[] = "@(#)colrops.c 2.4 10/2/92 LBL";
-#endif
-
 /*
  * Integer operations on COLR scanlines
  */
@@ -33,7 +29,7 @@ extern double	pow(double, double);
 #endif
 
 
-setcolrcor(double (*f)(double, double), double a2)
+int setcolrcor(double (*f)(double, double), double a2)
 		/* set brightness correction */
 {
 	double	mult;
@@ -53,7 +49,7 @@ setcolrcor(double (*f)(double, double), double a2)
 }
 
 
-setcolrinv(double (*f)(double, double), double a2)
+int setcolrinv(double (*f)(double, double), double a2)
 		/* set inverse brightness correction */
 {
 	double	mult;
@@ -79,7 +75,7 @@ setcolrinv(double (*f)(double, double), double a2)
 }
 
 
-setcolrgam(double g)			/* set gamma conversion */
+int setcolrgam(double g)			/* set gamma conversion */
 {
 	if (setcolrcor(pow, 1.0/g) < 0)
 		return(-1);
@@ -87,7 +83,7 @@ setcolrgam(double g)			/* set gamma conversion */
 }
 
 
-colrs_gambs(register COLR *scan, int len)
+int colrs_gambs(register COLR *scan, int len)
 		/* convert scanline of colrs to gamma bytes */
 {
 	register int	i, expo;
@@ -135,12 +131,12 @@ colrs_gambs(register COLR *scan, int len)
 }
 
 
-gambs_colrs(register COLR *scan, int len)
+int gambs_colrs(register COLR *scan, int len)
 	/* convert gamma bytes to colr scanline */
 {
 	register int	nexpo;
 
-	if (g_mant == NULL | g_nexp == NULL)
+	if (g_mant == NULL || g_nexp == NULL)
 		return(-1);
 	while (len-- > 0) {
 		nexpo = g_nexp[scan[0][RED]];
diff --git a/panda/src/pnmimagetypes/header.c b/panda/src/pnmimagetypes/header.c
index 66356092ac..c4199c0da1 100644
--- a/panda/src/pnmimagetypes/header.c
+++ b/panda/src/pnmimagetypes/header.c
@@ -1,9 +1,5 @@
 /* Copyright (c) 1994 Regents of the University of California */
 
-#ifndef lint
-static char SCCSid[] = "@(#)header.c 2.4 2/27/94 LBL";
-#endif
-
 /*
  *  header.c - routines for reading and writing information headers.
  *
@@ -42,6 +38,7 @@ newheader(char *s, register FILE *fp)		/* identifying line of information header
 }
 
 
+int 
 headidval(register char *r, register char *s)			/* get header id (return true if is id) */
 {
 	register char  *cp = HDRSTR;
@@ -54,6 +51,7 @@ headidval(register char *r, register char *s)			/* get header id (return true if
 }
 
 
+int
 isheadid(char *s)			/* check to see if line is header id */
 {
 	return(headidval(NULL, s));
@@ -82,6 +80,7 @@ printargs(int ac, char **av, register FILE *fp)		/* print arguments to a file */
 }
 
 
+int
 formatval(register char *r, register char *s)			/* get format value (return true if format) */
 {
 	register char  *cp = FMTSTR;
@@ -97,6 +96,7 @@ formatval(register char *r, register char *s)			/* get format value (return true
 }
 
 
+int
 isformat(char *s)			/* is line a format line? */
 {
 	return(formatval(NULL, s));
@@ -211,6 +211,7 @@ copymatch(char *pat, char *str)
  * if fout is not NULL.
  */
 
+int
 checkheader(FILE *fin, char *fmt, FILE *fout)
 {
 	struct check	cdat;
diff --git a/panda/src/pnmimagetypes/pnmFileTypeAlias.cxx b/panda/src/pnmimagetypes/pnmFileTypeAlias.cxx
index b166f22518..55d697bab6 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeAlias.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeAlias.cxx
@@ -82,6 +82,7 @@ get_suggested_extension() const {
 ////////////////////////////////////////////////////////////////////
 PNMReader *PNMFileTypeAlias::
 make_reader(FILE *file, bool owns_file, const string &magic_number) {
+  init_pnm();
   return new Reader(this, file, owns_file, magic_number);
 }
 
@@ -94,6 +95,7 @@ make_reader(FILE *file, bool owns_file, const string &magic_number) {
 ////////////////////////////////////////////////////////////////////
 PNMWriter *PNMFileTypeAlias::
 make_writer(FILE *file, bool owns_file) {
+  init_pnm();
   return new Writer(this, file, owns_file);
 }
 
diff --git a/panda/src/pnmimagetypes/pnmFileTypeBMP.cxx b/panda/src/pnmimagetypes/pnmFileTypeBMP.cxx
index 1aedc4ed52..ea479ac773 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeBMP.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeBMP.cxx
@@ -101,6 +101,7 @@ matches_magic_number(const string &magic_number) const {
 ////////////////////////////////////////////////////////////////////
 PNMReader *PNMFileTypeBMP::
 make_reader(FILE *file, bool owns_file, const string &magic_number) {
+  init_pnm();
   return new Reader(this, file, owns_file, magic_number);
 }
 
@@ -113,6 +114,7 @@ make_reader(FILE *file, bool owns_file, const string &magic_number) {
 ////////////////////////////////////////////////////////////////////
 PNMWriter *PNMFileTypeBMP::
 make_writer(FILE *file, bool owns_file) {
+  init_pnm();
   return new Writer(this, file, owns_file);
 }
 
diff --git a/panda/src/pnmimagetypes/pnmFileTypeBMPReader.cxx b/panda/src/pnmimagetypes/pnmFileTypeBMPReader.cxx
index bab54eb9e3..ff3dcf7d61 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeBMPReader.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeBMPReader.cxx
@@ -31,8 +31,11 @@ extern "C" {
  * without express or implied warranty.
  * 
  * $Log$
- * Revision 1.1  2000/10/04 01:14:42  drose
- * Initial revision
+ * Revision 1.2  2000/11/09 21:14:02  drose
+ * *** empty log message ***
+ *
+ * Revision 1.1.1.1  2000/10/04 01:14:42  drose
+ *
  *
  * Revision 1.10  1992/11/24  19:38:17  dws
  * Added code to verify that reading occurred at the correct offsets.
@@ -83,15 +86,10 @@ static void BMPreadinfoheader ARGS((FILE *fp, unsigned long *ppos,
     int *pclassv));
 static int BMPreadrgbtable ARGS((FILE *fp, unsigned long *ppos,
     unsigned short cBitCount, int classv, pixval *R, pixval *G, pixval *B));
-static int BMPreadrow ARGS((FILE *fp, unsigned long *ppos, pixel *row,
-    unsigned long cx, unsigned short cBitCount, pixval *R, pixval *G, pixval *B));
-static pixel ** BMPreadbits ARGS((FILE *fp, unsigned long *ppos,
-    unsigned long offBits, unsigned long cx, unsigned long cy,
-    unsigned short cBitCount, int classv, pixval *R, pixval *G, pixval *B));
 
 static const char *ifname = "BMP";
 static char     er_read[] = "%s: read error";
-static char     er_seek[] = "%s: seek error";
+//static char     er_seek[] = "%s: seek error";
 
 static int
 GetByte(FILE *fp)
@@ -500,7 +498,7 @@ Reader(PNMFileType *type, FILE *file, bool owns_file, string magic_number) :
     indexed = true;
     rc = BMPreadrgbtable(file, &pos, cBitCount, classv, R, G, B);
     
-    if (rc != BMPlenrgbtable(classv, cBitCount)) {
+    if (rc != (int)BMPlenrgbtable(classv, cBitCount)) {
       pnmimage_bmp_cat.warning()
 	<< rc << "-byte RGB table, expected "
 	<< BMPlenrgbtable(classv, cBitCount) << " bytes\n";
diff --git a/panda/src/pnmimagetypes/pnmFileTypeBMPWriter.cxx b/panda/src/pnmimagetypes/pnmFileTypeBMPWriter.cxx
index 71759e701c..87026f2a7b 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeBMPWriter.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeBMPWriter.cxx
@@ -35,8 +35,11 @@ extern "C" {
  * without express or implied warranty.
  *
  * $Log$
- * Revision 1.1  2000/10/04 01:14:42  drose
- * Initial revision
+ * Revision 1.2  2000/11/09 21:14:02  drose
+ * *** empty log message ***
+ *
+ * Revision 1.1.1.1  2000/10/04 01:14:42  drose
+ *
  *
  * Revision 1.9  1992/11/24  19:39:33  dws
  * Added copyright.
@@ -85,10 +88,6 @@ static int BMPwriteinfoheader ARGS((FILE *fp, int classv, unsigned long bitcount
 static int BMPwritergb ARGS((FILE *fp, int classv, pixval R, pixval G, pixval B));
 static int BMPwritergbtable ARGS((FILE *fp, int classv, int bpp, int colors,
     pixval *R, pixval *G, pixval *B));
-static int BMPwriterow ARGS((FILE *fp, pixel *row, unsigned long cx,
-    unsigned short bpp, colorhash_table cht));
-static int BMPwritebits ARGS((FILE *fp, unsigned long cx, unsigned long cy,
-    unsigned short cBitCount, pixel **pixels, colorhash_table cht));
 static int colorstobpp ARGS((int colors));
 static void BMPEncode ARGS((FILE *fp, int classv, int x, int y, pixel **pixels,
     int colors, colorhash_table cht, pixval *R, pixval *G, pixval *B));
diff --git a/panda/src/pnmimagetypes/pnmFileTypeIMG.cxx b/panda/src/pnmimagetypes/pnmFileTypeIMG.cxx
index 3a985c8600..612e832762 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeIMG.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeIMG.cxx
@@ -82,6 +82,7 @@ get_suggested_extension() const {
 ////////////////////////////////////////////////////////////////////
 PNMReader *PNMFileTypeIMG::
 make_reader(FILE *file, bool owns_file, const string &magic_number) {
+  init_pnm();
   return new Reader(this, file, owns_file, magic_number);
 }
 
@@ -94,6 +95,7 @@ make_reader(FILE *file, bool owns_file, const string &magic_number) {
 ////////////////////////////////////////////////////////////////////
 PNMWriter *PNMFileTypeIMG::
 make_writer(FILE *file, bool owns_file) {
+  init_pnm();
   return new Writer(this, file, owns_file);
 }
 
diff --git a/panda/src/pnmimagetypes/pnmFileTypePNM.cxx b/panda/src/pnmimagetypes/pnmFileTypePNM.cxx
index 42db279bba..81dcba5105 100644
--- a/panda/src/pnmimagetypes/pnmFileTypePNM.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypePNM.cxx
@@ -112,6 +112,7 @@ matches_magic_number(const string &magic_number) const {
 ////////////////////////////////////////////////////////////////////
 PNMReader *PNMFileTypePNM::
 make_reader(FILE *file, bool owns_file, const string &magic_number) {
+  init_pnm();
   return new Reader(this, file, owns_file, magic_number);
 }
 
@@ -124,6 +125,7 @@ make_reader(FILE *file, bool owns_file, const string &magic_number) {
 ////////////////////////////////////////////////////////////////////
 PNMWriter *PNMFileTypePNM::
 make_writer(FILE *file, bool owns_file) {
+  init_pnm();
   return new Writer(this, file, owns_file);
 }
 
@@ -284,6 +286,9 @@ write_header() {
   case PNMImageHeader::CT_four_channel:
     _pnm_format = PPM_TYPE;
     break;
+
+  default:
+    break;
   }
 
   pnm_writepnminit(_file, _x_size, _y_size, _maxval, _pnm_format, 0);
diff --git a/panda/src/pnmimagetypes/pnmFileTypeRadiance.cxx b/panda/src/pnmimagetypes/pnmFileTypeRadiance.cxx
index 090fdff0a1..6735ad27f0 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeRadiance.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeRadiance.cxx
@@ -121,6 +121,7 @@ matches_magic_number(const string &magic_number) const {
 ////////////////////////////////////////////////////////////////////
 PNMReader *PNMFileTypeRadiance::
 make_reader(FILE *file, bool owns_file, const string &magic_number) {
+  init_pnm();
   return new Reader(this, file, owns_file, magic_number);
 }
 
@@ -133,6 +134,7 @@ make_reader(FILE *file, bool owns_file, const string &magic_number) {
 ////////////////////////////////////////////////////////////////////
 PNMWriter *PNMFileTypeRadiance::
 make_writer(FILE *file, bool owns_file) {
+  init_pnm();
   return new Writer(this, file, owns_file);
 }
 
diff --git a/panda/src/pnmimagetypes/pnmFileTypeSGI.cxx b/panda/src/pnmimagetypes/pnmFileTypeSGI.cxx
index 435e57c045..52885f9b9d 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeSGI.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeSGI.cxx
@@ -105,6 +105,7 @@ matches_magic_number(const string &magic_number) const {
 ////////////////////////////////////////////////////////////////////
 PNMReader *PNMFileTypeSGI::
 make_reader(FILE *file, bool owns_file, const string &magic_number) {
+  init_pnm();
   return new Reader(this, file, owns_file, magic_number);
 }
 
@@ -117,6 +118,7 @@ make_reader(FILE *file, bool owns_file, const string &magic_number) {
 ////////////////////////////////////////////////////////////////////
 PNMWriter *PNMFileTypeSGI::
 make_writer(FILE *file, bool owns_file) {
+  init_pnm();
   return new Writer(this, file, owns_file);
 }
 
diff --git a/panda/src/pnmimagetypes/pnmFileTypeSGIReader.cxx b/panda/src/pnmimagetypes/pnmFileTypeSGIReader.cxx
index 5c61c9cbfa..9d3bd98125 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeSGIReader.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeSGIReader.cxx
@@ -48,7 +48,7 @@ static void * xmalloc (int bytes);
 #define MALLOC(n, type)     (type *)xmalloc((n) * sizeof(type))
 static char * compression_name (char compr);
 static void       read_bytes (FILE *ifp, int n, char *buf);
-static void read_header(FILE *ifp, Header *head, const string &magic_number);
+static bool read_header(FILE *ifp, Header *head, const string &magic_number);
 static TabEntry * read_table (FILE *ifp, int tablen);
 static void       read_channel (FILE *ifp, int xsize, int ysize, 
 				     int zsize, int bpc, TabEntry *table,
@@ -91,7 +91,9 @@ Reader(PNMFileType *type, FILE *file, bool owns_file, string magic_number) :
 
   Header head;
 
-  ::read_header(file, &head, magic_number);
+  if (!::read_header(file, &head, magic_number)) {
+    _is_valid = false;
+  }
 
   long pixmax = (head.bpc == 1) ? MAXVAL_BYTE : MAXVAL_WORD;
   if( pixmax > PNM_MAXMAXVAL ) {
@@ -115,7 +117,7 @@ Reader(PNMFileType *type, FILE *file, bool owns_file, string magic_number) :
 
   current_row = _y_size - 1;
 
-  if (pnmimage_sgi_cat.is_debug()) {
+  if (_is_valid && pnmimage_sgi_cat.is_debug()) {
     head.name[79] = '\0';  /* just to be safe */
     pnmimage_sgi_cat.debug()
       << "Read RGB image:\n"
@@ -214,9 +216,9 @@ read_row(xel *row_data, xelval *alpha_data) {
 
 
 
-static void
+static bool
 read_header(FILE *ifp, Header *head, const string &magic_number) {
-    nassertv(magic_number.size() == 4);
+    nassertr(magic_number.size() == 4, false);
     head->magic = 
       ((unsigned char)magic_number[0] << 8) |
       ((unsigned char)magic_number[1]);
@@ -233,15 +235,29 @@ read_header(FILE *ifp, Header *head, const string &magic_number) {
     head->colormap  = get_big_long(ifp);
     read_bytes(ifp, 404, head->dummy2);
 
-    if( head->magic != SGI_MAGIC )
-        pm_error("bad magic number - not an SGI image");
-    if( head->storage != 0 && head->storage != 1 )
-        pm_error("unknown compression type");
-    if( head->bpc < 1 || head->bpc > 2 )
-        pm_error("illegal precision value %d (only 1-2 allowed)", head->bpc );
-    if( head->colormap != CMAP_NORMAL )
-        pm_message("unsupported non-normal pixel data (%d)",
-		   head->colormap);
+    if (head->magic != SGI_MAGIC) {
+      pnmimage_sgi_cat.error()
+	<< "Invalid magic number: not an SGI image file.\n";
+      return false;
+    }
+
+    if (head->storage != 0 && head->storage != 1) {
+      pnmimage_sgi_cat.error()
+	<< "Unknown compression type.\n";
+      return false;
+    }
+
+    if (head->bpc < 1 || head->bpc > 2) {
+      pnmimage_sgi_cat.error()
+	<< "Illegal precision value " << head->bpc << " (only 1-2 allowed)\n";
+      return false;
+    }
+
+    if (head->colormap != CMAP_NORMAL) {
+      pnmimage_sgi_cat.error()
+	<< "Unsupported non-normal pixel data (" << head->colormap << ")\n";
+      return false;
+    }
 
     /* adjust ysize/zsize to dimension, just to be sure */
     switch( head->dimension ) {
@@ -262,14 +278,20 @@ read_header(FILE *ifp, Header *head, const string &magic_number) {
 	break;
 	
       default:
-	pm_message("%d-channel image, using only first 4 channels", head->zsize);
+	pnmimage_sgi_cat.warning()
+	  << "Using only first 4 channels of " << head->zsize
+	  << "-channel image.\n";
 	head->zsize = 4;
 	break;
       }
       break;
     default:
-      pm_error("illegal dimension value %d (only 1-3 allowed)", head->dimension);
+      pnmimage_sgi_cat.error()
+	<< "Illegal dimension value " << head->dimension 
+	<< " (only 1-3 allowed)\n";
+      return false;
     }
+    return true;
 }
 
 
diff --git a/panda/src/pnmimagetypes/pnmFileTypeSoftImage.cxx b/panda/src/pnmimagetypes/pnmFileTypeSoftImage.cxx
index 8a3c7c8cf2..c721498bc3 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeSoftImage.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeSoftImage.cxx
@@ -277,6 +277,7 @@ matches_magic_number(const string &magic_number) const {
 ////////////////////////////////////////////////////////////////////
 PNMReader *PNMFileTypeSoftImage::
 make_reader(FILE *file, bool owns_file, const string &magic_number) {
+  init_pnm();
   return new Reader(this, file, owns_file, magic_number);
 }
 
@@ -289,6 +290,7 @@ make_reader(FILE *file, bool owns_file, const string &magic_number) {
 ////////////////////////////////////////////////////////////////////
 PNMWriter *PNMFileTypeSoftImage::
 make_writer(FILE *file, bool owns_file) {
+  init_pnm();
   return new Writer(this, file, owns_file);
 }
 
@@ -344,8 +346,8 @@ Reader(PNMFileType *type, FILE *file, bool owns_file, string magic_number) :
   _x_size = read_ushort(_file);
   _y_size = read_ushort(_file);
 
-  float ratio = read_float(_file);
-  int fields = read_ushort(_file);
+  /* float ratio = */ read_float(_file);
+  /* int fields = */ read_ushort(_file);
   read_ushort(_file);
 
   int chained, size, channel;
@@ -464,8 +466,11 @@ read_row(xel *row_data, xelval *alpha_data) {
       return false;
     }
     break;
+
+  default:
+    break;
   }
-  
+
   return true;
 }
 
diff --git a/panda/src/pnmimagetypes/pnmFileTypeTIFF.cxx b/panda/src/pnmimagetypes/pnmFileTypeTIFF.cxx
index 9d24f2e7ad..7c10259aa5 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeTIFF.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeTIFF.cxx
@@ -199,6 +199,7 @@ matches_magic_number(const string &magic_number) const {
 ////////////////////////////////////////////////////////////////////
 PNMReader *PNMFileTypeTIFF::
 make_reader(FILE *file, bool owns_file, const string &magic_number) {
+  init_pnm();
   return new Reader(this, file, owns_file, magic_number);
 }
 
@@ -211,6 +212,7 @@ make_reader(FILE *file, bool owns_file, const string &magic_number) {
 ////////////////////////////////////////////////////////////////////
 PNMWriter *PNMFileTypeTIFF::
 make_writer(FILE *file, bool owns_file) {
+  init_pnm();
   return new Writer(this, file, owns_file);
 }
 
@@ -608,6 +610,9 @@ write_data(xel *array, xelval *alpha) {
     chv = (colorhist_vector) 0;
     grayscale = true;
     break;
+
+  default:
+    break;
   }
 
   /* Open output file. */
@@ -651,6 +656,9 @@ write_data(xel *array, xelval *alpha) {
     i = 8 / bitspersample;
     bytesperrow = ( _x_size + i - 1 ) / i;
     break;
+
+  default:
+    break;
   }
 
   if ( tiff_rowsperstrip == 0 )
diff --git a/panda/src/pnmimagetypes/pnmFileTypeYUV.cxx b/panda/src/pnmimagetypes/pnmFileTypeYUV.cxx
index d4b2725fd5..b69275bc3f 100644
--- a/panda/src/pnmimagetypes/pnmFileTypeYUV.cxx
+++ b/panda/src/pnmimagetypes/pnmFileTypeYUV.cxx
@@ -125,6 +125,7 @@ get_suggested_extension() const {
 ////////////////////////////////////////////////////////////////////
 PNMReader *PNMFileTypeYUV::
 make_reader(FILE *file, bool owns_file, const string &magic_number) {
+  init_pnm();
   return new Reader(this, file, owns_file, magic_number);
 }
 
@@ -137,6 +138,7 @@ make_reader(FILE *file, bool owns_file, const string &magic_number) {
 ////////////////////////////////////////////////////////////////////
 PNMWriter *PNMFileTypeYUV::
 make_writer(FILE *file, bool owns_file) {
+  init_pnm();
   return new Writer(this, file, owns_file);
 }
 
@@ -218,7 +220,7 @@ supports_read_row() const {
 ////////////////////////////////////////////////////////////////////
 bool PNMFileTypeYUV::Reader::
 read_row(xel *row_data, xelval *) {
-  long tmp, y, u, v, y1, r, g, b;
+  long y, u, v, y1, r, g, b;
   unsigned char *yuvptr;
   int col;
 
diff --git a/panda/src/pnmimagetypes/resolu.c b/panda/src/pnmimagetypes/resolu.c
index 586a968af8..9e520abd36 100644
--- a/panda/src/pnmimagetypes/resolu.c
+++ b/panda/src/pnmimagetypes/resolu.c
@@ -1,9 +1,5 @@
 /* Copyright (c) 1991 Regents of the University of California */
 
-#ifndef lint
-static char SCCSid[] = "@(#)resolu.c 2.2 11/28/91 LBL";
-#endif
-
 /*
  * Read and write image resolutions.
  */