Fix up some coverity issues, and other warnings

CIDs: 341120, 341119, 341118, 341117, 341116, 341115, 341114, 341113, 341112,
341111, 341110, 341109, 341108, 341107, 341106, 341105, 341104, 341103, 341102,
341101.

Mostly examples of gp_fseek and sscanf ignoring return values.

15 files changed, 80 insertions, 63 deletions

diff --git a/base/gp_unifs.c b/base/gp_unifs.c
index c900326d4..f0deeb2a9 100644
--- a/base/gp_unifs.c
+++ b/base/gp_unifs.c
@@ -107,20 +107,20 @@ gp_open_scratch_file_impl(const gs_memory_t *mem,
 
         /* save the old filename template in case mkstemp fails */
         memcpy(ofname, fname, gp_file_name_sizeof);
-#ifdef HAVE_MKSTEMP64
+#  ifdef HAVE_MKSTEMP64
         file = mkstemp64(fname);
-#else
+#  else
         file = mkstemp(fname);
-#endif
+#  endif
         if (file < -1) {
             emprintf1(mem, "**** Could not open temporary file %s\n", ofname);
             return NULL;
         }
-#if defined(O_LARGEFILE) && defined(__hpux)
+#  if defined(O_LARGEFILE) && defined(__hpux)
         fcntl(file, F_SETFD, fcntl(file, F_GETFD) | O_LARGEFILE);
-#else
+#  else
         /* Fixme : what to do with b64 and 32-bit mkstemp? Unimplemented. */
-#endif
+#  endif
 
         fp = fdopen(file, mode);
         if (fp == NULL) {
diff --git a/base/mkromfs.c b/base/mkromfs.c
index ff18062b8..bd61f489e 100644
--- a/base/mkromfs.c
+++ b/base/mkromfs.c
@@ -615,8 +615,8 @@ typedef struct {
     int outmax;
     int buffercopy;
     int wasascii;
-    char *bufferin;
-    char *bufferout;
+    unsigned char *bufferin;
+    unsigned char *bufferout;
     psc_getc *pgetc;
     psc_ungetc *unpgetc;
     psc_feof *peof;
@@ -1026,7 +1026,7 @@ static int pscompact_isname(pscompstate *psc, int *i)
     if (psc->bufferin[0] == '/')
         off = 1;
     for (n = 0; n < sizeof(pscompact_names)/sizeof(char *); n++) {
-        if (strncmp(pscompact_names[n], &psc->bufferin[off], psc->inpos-off) == 0) {
+        if (strncmp(pscompact_names[n], (const char *)&psc->bufferin[off], psc->inpos-off) == 0) {
             /* Match! */
             if (off)
                 *i = -1-n;
@@ -1048,7 +1048,7 @@ static int pscompact_isint(pscompstate *psc, int *i)
     if (pos >= psc->inpos)
         return 0;
     if ((psc->inpos > pos+3) &&
-        (strncmp(&psc->bufferin[pos], "16#", 3) == 0)) {
+        (strncmp((const char *)&psc->bufferin[pos], "16#", 3) == 0)) {
         /* hex */
         int v = 0;
         pos += 3;
@@ -1080,12 +1080,12 @@ static int pscompact_isint(pscompstate *psc, int *i)
         psc->bufferin = realloc(psc->bufferin, psc->inmax);
     }
     psc->bufferin[psc->inpos] = 0;
-    *i = atoi(psc->bufferin);
+    *i = atoi((const char *)psc->bufferin);
 
     /* Check for 32bit overflow */
     if (psc->inpos > 9) {
         char *end;
-        double d = strtod(psc->bufferin, &end);
+        double d = strtod((const char *)psc->bufferin, &end);
         if (d != (double)(int)*i)
             return 0;
     }
@@ -1121,7 +1121,7 @@ static int pscompact_isfloat(pscompstate *psc, float *f)
         psc->bufferin = realloc(psc->bufferin, psc->inmax);
     }
     psc->bufferin[psc->inpos] = 0;
-    *f = atof(psc->bufferin);
+    *f = atof((const char *)psc->bufferin);
     return 1;
 }
 
@@ -1337,7 +1337,7 @@ static unsigned long pscompact_getcompactedblock(pscompstate *psc, unsigned char
                         }
                     }
                     if ((psc->inpos == 4) &&
-                        (strncmp(psc->bufferin, "true", 4) == 0)) {
+                        (strncmp((const char *)psc->bufferin, "true", 4) == 0)) {
                         /* Encode as a 32 bit integer */
                         psc->bufferout[0] = 141;
                         psc->bufferout[1] = 1;
@@ -1350,7 +1350,7 @@ static unsigned long pscompact_getcompactedblock(pscompstate *psc, unsigned char
                         break;
                     }
                     if ((psc->inpos == 5) &&
-                        (strncmp(psc->bufferin, "false", 5) == 0)) {
+                        (strncmp((const char *)psc->bufferin, "false", 5) == 0)) {
                         /* Encode as a 32 bit integer */
                         psc->bufferout[0] = 141;
                         psc->bufferout[1] = 0;
@@ -1568,7 +1568,7 @@ static unsigned long pscompact_getcompactedblock(pscompstate *psc, unsigned char
                 c = psc->pgetc(psc->file);
                 if ((c == 13) || (c == 10)) {
                     if ((psc->inpos >= 3) &&
-                        (strncmp(psc->bufferin, "END", 3) == 0)) {
+                        (strncmp((const char *)psc->bufferin, "END", 3) == 0)) {
                         /* Special comment to retain */
                         pscompact_bufferatstart(psc, '%');
                         pscompact_buffer(psc, 10);
@@ -1576,7 +1576,7 @@ static unsigned long pscompact_getcompactedblock(pscompstate *psc, unsigned char
                         break;
                     }
                     if ((psc->inpos >= 7) &&
-                        (strncmp(psc->bufferin, "NAMESOK", 7) == 0)) {
+                        (strncmp((const char *)psc->bufferin, "NAMESOK", 7) == 0)) {
                         psc->names = 1;
                         pscompact_bufferatstart(psc, '%');
                         pscompact_buffer(psc, 10);
@@ -1584,7 +1584,7 @@ static unsigned long pscompact_getcompactedblock(pscompstate *psc, unsigned char
                         break;
                     }
                     if ((psc->inpos >= 8) &&
-                        (strncmp(psc->bufferin, "BINARYOK", 8) == 0)) {
+                        (strncmp((const char *)psc->bufferin, "BINARYOK", 8) == 0)) {
                         psc->binary = 1;
                         pscompact_bufferatstart(psc, '%');
                         pscompact_buffer(psc, 10);
diff --git a/contrib/pcl3/eprn/pagecount.c b/contrib/pcl3/eprn/pagecount.c
index f5ba13d6e..a635bd451 100644
--- a/contrib/pcl3/eprn/pagecount.c
+++ b/contrib/pcl3/eprn/pagecount.c
@@ -142,7 +142,7 @@ int pcf_getcount(const gs_memory_t *mem, const char *filename, unsigned long *co
   gp_file *f;
 
   /* Should we use a page count file? */
-  if (filename == NULL || *filename == '\0') return 0;
+  if (filename == NULL || *filename == '\0' || count == NULL) return 0;
 
   /* If the file does not exist, the page count is taken to be zero. */
   if (access(filename, F_OK) != 0) {
@@ -153,7 +153,7 @@ int pcf_getcount(const gs_memory_t *mem, const char *filename, unsigned long *co
   /* Open the file */
   if ((f = gp_fopen(mem, filename, "r")) == NULL) {
     errprintf(mem, ERRPREFIX "Cannot open page count file `%s': %s.\n",
-      filename, strerror(gp_ferror(f)));
+      filename, strerror(errno));
     return -1;
   }
 
@@ -206,7 +206,7 @@ int pcf_inccount(const gs_memory_t *mem, const char *filename, unsigned long by)
   */
   if ((f = gp_fopen(mem, filename, "a+")) == NULL) {
     errprintf(mem, ERRPREFIX "Cannot open page count file `%s': %s.\n",
-      filename, strerror(gp_ferror(f)));
+      filename, strerror(errno));
     return 1;
   }
 
@@ -239,7 +239,7 @@ int pcf_inccount(const gs_memory_t *mem, const char *filename, unsigned long by)
     if (f1 == NULL) {
       errprintf(mem, ERRPREFIX
         "Error opening page count file `%s' a second time: %s.\n",
-        filename, strerror(gp_ferror(f1)));
+        filename, strerror(errno));
       rc = 1;
     }
     else {
diff --git a/contrib/pcl3/src/gdevpcl3.c b/contrib/pcl3/src/gdevpcl3.c
index c6e348520..7582c9bc7 100644
--- a/contrib/pcl3/src/gdevpcl3.c
+++ b/contrib/pcl3/src/gdevpcl3.c
@@ -1467,7 +1467,7 @@ static int pcl3_print_page(gx_device_printer *device, gp_file *out)
      printer first */
   if (gdev_prn_file_is_new(device) || !dev->configured ||
       dev->configure_every_page) {
-    guard(pcl3_init_file(out, &dev->file_data))
+    guard(pcl3_init_file(device->memory, out, &dev->file_data))
     dev->configured = true;
   }
 
diff --git a/contrib/pcl3/src/pclgen.c b/contrib/pcl3/src/pclgen.c
index 9426292d6..0670d8867 100644
--- a/contrib/pcl3/src/pclgen.c
+++ b/contrib/pcl3/src/pclgen.c
@@ -148,7 +148,7 @@ static void send_ERG(gp_file *out, pcl_Level level)
 
 ******************************************************************************/
 
-int pcl3_init_file(gp_file *out, pcl_FileData *data)
+int pcl3_init_file(gs_memory_t *mem, gp_file *out, pcl_FileData *data)
 {
   pcl_bool needs_CRD = (data->level == pcl_level_3plus_CRD_only);
     /* Do we need Configure Raster Data? */
@@ -162,7 +162,7 @@ int pcl3_init_file(gp_file *out, pcl_FileData *data)
 
     invalid = (out == NULL || data == NULL);
     if (invalid)
-      errprintf(out->memory, ERRPREF "Null pointer passed to pcl3_init_file().\n");
+      errprintf(mem, ERRPREF "Null pointer passed to pcl3_init_file().\n");
     else {
       /* Palette und colorants */
       switch(data->palette) {
@@ -175,7 +175,7 @@ int pcl3_init_file(gp_file *out, pcl_FileData *data)
         default: invalid = data->number_of_colorants <= 0;
       }
       if (invalid)
-        errprintf(out->memory, ERRPREF
+        errprintf(mem, ERRPREF
           "Palette specification and number of colorants are inconsistent.\n");
       else {
         if (data->colorant == NULL) colorant = data->colorant_array;
@@ -187,7 +187,7 @@ int pcl3_init_file(gp_file *out, pcl_FileData *data)
         for (j = 0; j < data->number_of_colorants; j++) {
           if (colorant[j].hres <= 0 || colorant[j].vres <= 0) {
             invalid = TRUE;
-            errprintf(out->memory, ERRPREF
+            errprintf(mem, ERRPREF
               "The resolution for colorant %d is not positive: %u x %u ppi.\n",
               j, colorant[j].hres, colorant[j].vres);
           }
@@ -199,7 +199,7 @@ int pcl3_init_file(gp_file *out, pcl_FileData *data)
           }
           if (colorant[j].levels < 2 || 0xFFFF < colorant[j].levels) {
             invalid = TRUE;
-            errprintf(out->memory, ERRPREF "The number of intensity levels for "
+            errprintf(mem, ERRPREF "The number of intensity levels for "
               "colorant %d is %u instead of at least 2 and at most 65535.\n",
               j, colorant[j].levels);
             /* Actually, DJ6/8 p. 68 requires the levels to be in the range
@@ -235,21 +235,21 @@ int pcl3_init_file(gp_file *out, pcl_FileData *data)
             */
             if (colorant[j].vres % data->minvres != 0) {
               invalid = TRUE;
-              errprintf(out->memory, ERRPREF
+              errprintf(mem, ERRPREF
                 "The vertical resolution for colorant %d (%u ppi) is not a "
                 "multiple of the lowest vertical resolution (%u ppi).\n",
                 j, colorant[j].vres, data->minvres);
             }
             if (maxhres % colorant[j].hres != 0) {
               invalid = TRUE;
-              errprintf(out->memory, ERRPREF
+              errprintf(mem, ERRPREF
                 "The highest horizontal resolution (%u ppi) is not a multiple "
                 "of the horizontal resolution for colorant %d (%u ppi).\n",
                 maxhres, j, colorant[j].hres);
             }
             if (maxvres % colorant[j].vres != 0) {
               invalid = TRUE;
-              errprintf(out->memory, ERRPREF
+              errprintf(mem, ERRPREF
                 "The highest vertical resolution (%u ppi) is not a multiple "
                 "of the vertical resolution for colorant %d (%u ppi).\n",
                 maxvres, j, colorant[j].vres);
@@ -260,32 +260,32 @@ int pcl3_init_file(gp_file *out, pcl_FileData *data)
       if (needs_CRD && data->palette == pcl_RGB) {
         invalid = TRUE;
         if (data->level == pcl_level_3plus_CRD_only)
-          errprintf(out->memory, ERRPREF
+          errprintf(mem, ERRPREF
             "You can't use an RGB palette at the requested PCL level.\n");
         else
-          errprintf(out->memory, ERRPREF "The specified structure of resolutions and intensity "
+          errprintf(mem, ERRPREF "The specified structure of resolutions and intensity "
             "levels is not possible with an RGB palette.\n");
       }
       if (needs_CRD && !pcl_has_CRD(data->level)) {
         invalid = TRUE;
-        errprintf(out->memory, ERRPREF "The specified structure of resolutions and intensity "
+        errprintf(mem, ERRPREF "The specified structure of resolutions and intensity "
           "levels is not possible at the requested PCL level.\n");
       }
       if (data->palette == pcl_any_palette) {
         needs_CRD = TRUE;
         if (!pcl_has_CRD(data->level)) {
           invalid = TRUE;
-          errprintf(out->memory, ERRPREF "The specified palette is not possible at the "
+          errprintf(mem, ERRPREF "The specified palette is not possible at the "
             "requested PCL level.\n");
         }
       }
       if (needs_CRD && (maxhres > 0xFFFF || maxvres > 0xFFFF)) {
-        errprintf(out->memory, ERRPREF "Resolutions may be at most 65535 ppi when more than one "
+        errprintf(mem, ERRPREF "Resolutions may be at most 65535 ppi when more than one "
           "resolution or more than two intensity levels are requested.\n");
         invalid = TRUE;
       }
       if (data->order_CMYK && data->palette != pcl_CMYK) {
-        errprintf(out->memory, ERRPREF
+        errprintf(mem, ERRPREF
           "Ordering bit planes as CMYK instead of KCMY is only meaningful\n"
           "  for a CMYK palette.\n");
         invalid = TRUE;
@@ -299,7 +299,7 @@ int pcl3_init_file(gp_file *out, pcl_FileData *data)
            exception of '"' (PJLTRM, with some corrections). */
         while (*s != '\0' && (*s == '\t' || (32 <= *s && *s != '"'))) s++;
         if (*s != '\0') {
-          errprintf(out->memory,
+          errprintf(mem,
             ERRPREF "Illegal character in PJL job name (code 0x%02X).\n", *s);
           invalid = TRUE;
         }
@@ -310,7 +310,7 @@ int pcl3_init_file(gp_file *out, pcl_FileData *data)
            There would also be a warning for an empty string but we treat that
            case differently anyway (see below). */
         if (strlen(data->PJL_job) > 80) {
-          errprintf(out->memory, ERRPREF "PJL job name is too long (more than 80 characters).\n");
+          errprintf(mem, ERRPREF "PJL job name is too long (more than 80 characters).\n");
           invalid = TRUE;
         }
       }
@@ -326,11 +326,11 @@ int pcl3_init_file(gp_file *out, pcl_FileData *data)
         if (is_letter(*s)) do s++; while (is_letter(*s) || is_digit(*s));
 
         if (*data->PJL_language == '\0') {
-          errprintf(out->memory, ERRPREF "Empty PJL language name.\n");
+          errprintf(mem, ERRPREF "Empty PJL language name.\n");
           invalid = TRUE;
         }
         else if (*s != '\0') {
-          errprintf(out->memory,
+          errprintf(mem,
             ERRPREF "Illegal character in PJL language name (code 0x%02X).\n",
             *s);
           invalid = TRUE;
@@ -487,7 +487,7 @@ int pcl3_init_file(gp_file *out, pcl_FileData *data)
   }
 
   if (gp_ferror(out)) {
-    errprintf(out->memory, ERRPREF "Unidentified system error while writing the output file.\n");
+    errprintf(mem, ERRPREF "Unidentified system error while writing the output file.\n");
     return -1;
   }
 
diff --git a/contrib/pcl3/src/pclgen.h b/contrib/pcl3/src/pclgen.h
index 8fa36c28f..d314d8d15 100644
--- a/contrib/pcl3/src/pclgen.h
+++ b/contrib/pcl3/src/pclgen.h
@@ -410,7 +410,7 @@ extern int pcl_compress(pcl_Compression method, const pcl_OctetString *in,
   const pcl_OctetString *prev, pcl_OctetString *out);
 
 /* File and page functions */
-extern int pcl3_init_file(gp_file *out, pcl_FileData *global);
+extern int pcl3_init_file(gs_memory_t *mem, gp_file *out, pcl_FileData *global);
 extern int pcl3_begin_page(gp_file *out, pcl_FileData *global);
 extern int pcl3_end_page(gp_file *out, pcl_FileData *global);
 extern int pcl3_end_file(gp_file *out, pcl_FileData *global);
diff --git a/devices/gdevdfax.c b/devices/gdevdfax.c
index 905227db5..cfd2a6960 100644
--- a/devices/gdevdfax.c
+++ b/devices/gdevdfax.c
@@ -88,7 +88,10 @@ dfax_print_page(gx_device_printer *dev, gp_file *prn_stream)
                 { hdr[45] = 0x40; hdr[29] = 1; }	/* high res */
         else
                 { hdr[45] = hdr[29] = 0; }		/* low res */
-        gp_fseek(prn_stream, 0, SEEK_END);
+        code = gp_fseek(prn_stream, 0, SEEK_END);
+        if (code < 0)
+            return_error(gs_error_ioerror);
+
         gp_fwrite(hdr, sizeof(hdr), 1, prn_stream);
 
         /* Write the page */
diff --git a/devices/gdevpsd.c b/devices/gdevpsd.c
index 1babc604f..9212ff9dd 100644
--- a/devices/gdevpsd.c
+++ b/devices/gdevpsd.c
@@ -1294,10 +1294,18 @@ psd_write_image_data(psd_write_ctx *xc, gx_device_printer *pdev)
                 memset(sep_line,255,octets_per_line);
                 psd_write(xc, sep_line, octets_per_line);
             }
-            gp_fseek(xc->f, (xc->height-1) * octets_per_line, SEEK_CUR);
+            code = gp_fseek(xc->f, ((gs_offset_t)xc->height-1) * octets_per_line, SEEK_CUR);
+            if (code < 0) {
+                code = gs_note_error(gs_error_ioerror);
+                goto cleanup;
+            }
         }
         if (j < xc->height-1)
-            gp_fseek(xc->f, -(num_comp * xc->height - 1) * octets_per_line, SEEK_CUR);
+            code = gp_fseek(xc->f, -((gs_offset_t)num_comp * xc->height - 1) * octets_per_line, SEEK_CUR);
+            if (code < 0) {
+                code = gs_note_error(gs_error_ioerror);
+                goto cleanup;
+            }
     }
 
 cleanup:
diff --git a/devices/vector/gdevpdf.c b/devices/vector/gdevpdf.c
index e8deed46e..d1db9b36a 100644
--- a/devices/vector/gdevpdf.c
+++ b/devices/vector/gdevpdf.c
@@ -1587,7 +1587,7 @@ rewrite_object(gx_device_pdf *const pdev, pdf_linearisation_t *linear_params, in
                 target--;
             }while (*target >= '0' && *target <= '9');
             target++;
-            sscanf(target, "%d 0 R", &ID);
+            (void)sscanf(target, "%d 0 R", &ID);
             gp_fwrite(source, target - source, 1, linear_params->Lin_File.file);
             gs_sprintf(Buf, "%d 0 R", pdev->ResourceUsage[ID].NewObjectNumber);
             gp_fwrite(Buf, strlen(Buf), 1, linear_params->Lin_File.file);
diff --git a/devices/vector/gdevxps.c b/devices/vector/gdevxps.c
index 2ba26defb..71ca1f745 100644
--- a/devices/vector/gdevxps.c
+++ b/devices/vector/gdevxps.c
@@ -726,7 +726,7 @@ zip_close_archive_file(gx_device_xps *xps_dev, const char *filename)
             return gs_throw_code(gs_error_Fatal);
 
         crc = crc32(0L, Z_NULL, 0);
-        gp_fseek(fp, 0, SEEK_SET);
+        gp_rewind(fp);
         while (!gp_feof(fp)) {
             nread = gp_fread(buf, 1, sizeof(buf), fp);
             crc = crc32(crc, buf, nread);
diff --git a/pcl/pl/pjparse.c b/pcl/pl/pjparse.c
index 007dd461e..ab8f91394 100644
--- a/pcl/pl/pjparse.c
+++ b/pcl/pl/pjparse.c
@@ -1142,8 +1142,11 @@ pjl_get_named_resource_size(pjl_parser_state_t * pst, char *name)
 
     if (fp == NULL)
         return 0;
-    gp_fseek(fp, 0L, SEEK_END);
-    size = gp_ftell(fp);
+    size = gp_fseek(fp, 0L, SEEK_END);
+    if (size >= 0)
+        size = gp_ftell(fp);
+    else
+        size = 0;
     gp_fclose(fp);
     return size;
 }
@@ -1159,8 +1162,9 @@ pjl_get_named_resource(pjl_parser_state * pst, char *name, byte * data)
 
     if (fp == NULL)
         return 0;
-    gp_fseek(fp, 0L, SEEK_END);
-    size = gp_ftell(fp);
+    size = gp_fseek(fp, 0L, SEEK_END);
+    if (size >= 0)
+        size = gp_ftell(fp);
     gp_rewind(fp);
     if (size < 0 || (size != gp_fread(data, 1, size, fp))) {
         code = -1;
diff --git a/pcl/pl/plmain.c b/pcl/pl/plmain.c
index 1ce87ab61..067d459a5 100644
--- a/pcl/pl/plmain.c
+++ b/pcl/pl/plmain.c
@@ -1456,7 +1456,7 @@ pl_main_process_options(pl_main_instance_t * pmi, arg_list * pal,
                 if (*arg == 0)
                     gs_debug['#'] = 1;
                 else
-                    sscanf(arg, "%d", &pmi->error_report);
+                    (void)sscanf(arg, "%d", &pmi->error_report);
                 break;
             case 'f':
                 code = arg_next(pal, (const char **)&arg, pmi->memory);
diff --git a/psi/imainarg.c b/psi/imainarg.c
index 9739317eb..67bccec06 100644
--- a/psi/imainarg.c
+++ b/psi/imainarg.c
@@ -578,8 +578,6 @@ run_stdin:
                 if (code > 0)
                     code = argproc(minst, arg);
                 (void)gs_remove_control_path(minst->heap, gs_permit_file_reading, arg);
-                if (code < 0)
-                    return code;
                 minst->run_buffer_size = bsize;
                 if (code < 0)
                     return code;
@@ -644,7 +642,7 @@ run_stdin:
                 long msize = 0;
                 gs_malloc_memory_t *rawheap = gs_malloc_wrapped_contents(minst->heap);
 
-                sscanf((const char *)arg, "%ld", &msize);
+                (void)sscanf((const char *)arg, "%ld", &msize);
                 if (msize <= 0 || msize > max_long >> 10) {
                     outprintf(minst->heap, "-K<numK> must have 1 <= numK <= %ld\n",
                               max_long >> 10);
@@ -657,7 +655,7 @@ run_stdin:
             {
                 unsigned msize = 0;
 
-                sscanf((const char *)arg, "%u", &msize);
+                (void)sscanf((const char *)arg, "%u", &msize);
                 if (msize <= 0 || msize >= (max_uint >> 10)) {
                     outprintf(minst->heap, "-M must be between 1 and %d\n", (int)((max_uint >> 10) - 1));
                     return gs_error_Fatal;
@@ -669,7 +667,7 @@ run_stdin:
             {
                 unsigned nsize = 0;
 
-                sscanf((const char *)arg, "%d", &nsize);
+                (void)sscanf((const char *)arg, "%d", &nsize);
                 if (nsize < 2 || nsize > (max_uint >> 10)) {
                     outprintf(minst->heap, "-N must be between 2 and %d\n", (int)(max_uint >> 10));
                     return gs_error_Fatal;
diff --git a/psi/iutil.c b/psi/iutil.c
index 41b5cdf2f..55d0e5217 100644
--- a/psi/iutil.c
+++ b/psi/iutil.c
@@ -341,7 +341,7 @@ obj_cvp(const ref * op, byte * str, uint len, uint * prlen,
             float scanned;
 
             gs_sprintf(buf, "%g", value);
-            sscanf(buf, "%f", &scanned);
+            (void)sscanf(buf, "%f", &scanned);
             if (scanned != value)
                 gs_sprintf(buf, "%.9g", value);
             ensure_dot(buf);
@@ -572,7 +572,7 @@ ensure_dot(char *buf)
     char *pe = strchr(buf, 'e');
     if (pe) {
         int i;
-        sscanf(pe + 1, "%d", &i);
+        (void)sscanf(pe + 1, "%d", &i);
         /* MSVC .net 2005 express doesn't support "%+02d" */
         if (i >= 0)
             gs_sprintf(pe + 1, "+%02d", i);
diff --git a/xps/xpszip.c b/xps/xpszip.c
index 06dc9af4d..bf897dad1 100644
--- a/xps/xpszip.c
+++ b/xps/xpszip.c
@@ -302,7 +302,9 @@ xps_find_and_read_zip_dir(xps_context_t *ctx)
     int i, n;
     char buf[512];
 
-    xps_fseek(ctx->file, 0, SEEK_END);
+    if (xps_fseek(ctx->file, 0, SEEK_END) < 0)
+        return gs_throw(-1, "seek to end failed.");
+
     filesize = xps_ftell(ctx->file);
 
     maxback = MIN(filesize, 0xFFFF + sizeof buf);
@@ -310,7 +312,8 @@ xps_find_and_read_zip_dir(xps_context_t *ctx)
 
     while (back < maxback)
     {
-        xps_fseek(ctx->file, filesize - back, 0);
+        if (xps_fseek(ctx->file, filesize - back, 0) < 0)
+            return gs_throw1(gs_error_ioerror, "xps_fseek to %d failed.\n", filesize - back);
 
         n = xps_fread(buf, 1, sizeof buf, ctx->file);
         if (n < 0)
@@ -478,7 +481,8 @@ xps_read_dir_part(xps_context_t *ctx, const char *name)
         if (!file)
             break;
         count ++;
-        xps_fseek(file, 0, SEEK_END);
+        if (xps_fseek(file, 0, SEEK_END) < 0)
+            break;;
         size += xps_ftell(file);
         gp_fclose(file);
     }