CQ: we should check the return value of lseek (#5783)

An attempt to unify checks and error messages.

There are more places where `lseek` return value should be checked, but I don't have time to work on them now.

* CQ: we should check the return value of lseek
An attempt to unify checks and error messages

* r.random: remove unnecesarry lseek

Rewinding a raster map can lead to lseek errors and generally
should not be done, as raster reading functions perform seek
on their own if required.

* QA: add more checks for lseek return value

* QC: finish cleaning up lseek error handling:

* no need to cast -1 to off_t as we do not use K&R C
* make error message arguments relocable
* unify error messges
* add missing includes for error reporting

* Fix wording of error message on seek fail

* Clean up unintentional changes

Author: marisn

imagery/i.ortho.photo/i.ortho.rectify/readcell.c

@@ -135,7 +135,7 @@ block *get_block(struct cache *c, int idx)
     c->grid[idx] = p;
     c->refs[replace] = idx;
 
-    if (lseek(c->fd, offset, SEEK_SET) < 0)
+    if (lseek(c->fd, offset, SEEK_SET) == -1)
         G_fatal_error(_("Error seeking on segment file"));
 
     if (read(c->fd, p, sizeof(block)) < 0)

imagery/i.rectify/readcell.c

@@ -119,7 +119,7 @@ block *get_block(struct cache *c, int idx)
     c->grid[idx] = p;
     c->refs[replace] = idx;
 
-    if (lseek(c->fd, offset, SEEK_SET) < 0)
+    if (lseek(c->fd, offset, SEEK_SET) == -1)
         G_fatal_error(_("Error seeking on segment file"));
 
     if (read(c->fd, p, sizeof(block)) < 0)

imagery/i.segment/cluster.c

@@ -22,6 +22,9 @@
 #include <unistd.h>
 #include <math.h>
 #include <time.h>
+#include <string.h>
+#include <errno.h>
+
 #include <grass/gis.h>
 #include <grass/raster.h>
 #include <grass/glocale.h>
@@ -421,7 +424,11 @@ CELL cluster_bands(struct globals *globals)
         G_fatal_error(_("Too many objects: integer overflow"));
 
     /* rewind temp file */
-    lseek(cfd, 0, SEEK_SET);
+    if (lseek(cfd, 0, SEEK_SET) == -1) {
+        int err = errno;
+        G_fatal_error(_("File read/write operation failed: %s (%d)"),
+                      strerror(err), err);
+    }
 
     /****************************************************
      *                      PASS 2                      *

lib/gis/open.c

@@ -192,7 +192,12 @@ int G_open_update(const char *element, const char *name)
 
     fd = G__open(element, name, G_mapset(), 2);
     if (fd >= 0)
-        lseek(fd, 0L, SEEK_END);
+        if (lseek(fd, 0L, SEEK_END) == -1) {
+            int err = errno;
+            G_warning(_("File read/write operation failed: %s (%d)"),
+                      strerror(err), err);
+            return -1;
+        }
 
     return fd;
 }
@@ -279,7 +284,12 @@ FILE *G_fopen_append(const char *element, const char *name)
     fd = G__open(element, name, G_mapset(), 2);
     if (fd < 0)
         return (FILE *)0;
-    lseek(fd, 0L, SEEK_END);
+    if (lseek(fd, 0L, SEEK_END) == -1) {
+        int err = errno;
+        G_warning(_("File read/write operation failed: %s (%d)"), strerror(err),
+                  err);
+        return NULL;
+    }
 
     G_debug(2, "\tfile open: append (mode = a)");
     return fdopen(fd, "a");
@@ -307,7 +317,12 @@ FILE *G_fopen_modify(const char *element, const char *name)
     fd = G__open(element, name, G_mapset(), 2);
     if (fd < 0)
         return (FILE *)0;
-    lseek(fd, 0L, SEEK_END);
+    if (lseek(fd, 0L, SEEK_END) == -1) {
+        int err = errno;
+        G_warning(_("File read/write operation failed: %s (%d)"), strerror(err),
+                  err);
+        return NULL;
+    }
 
     G_debug(2, "\tfile open: modify (mode = r+)");
     return fdopen(fd, "r+");

lib/gis/open_misc.c

@@ -155,7 +155,12 @@ int G_open_update_misc(const char *dir, const char *element, const char *name)
 
     fd = G__open_misc(dir, element, name, G_mapset(), 2);
     if (fd >= 0)
-        lseek(fd, 0L, SEEK_END);
+        if (lseek(fd, 0L, SEEK_END) == -1) {
+            int err = errno;
+            G_warning(_("File read/write operation failed: %s (%d)"),
+                      strerror(err), err);
+            return -1;
+        }
 
     return fd;
 }
@@ -222,7 +227,12 @@ FILE *G_fopen_append_misc(const char *dir, const char *element,
     fd = G__open_misc(dir, element, name, G_mapset(), 2);
     if (fd < 0)
         return (FILE *)0;
-    lseek(fd, 0L, SEEK_END);
+    if (lseek(fd, 0L, SEEK_END) == -1) {
+        int err = errno;
+        G_warning(_("File read/write operation failed: %s (%d)"), strerror(err),
+                  err);
+        return (FILE *)-1;
+    }
 
     return fdopen(fd, "a");
 }
@@ -235,7 +245,12 @@ FILE *G_fopen_modify_misc(const char *dir, const char *element,
     fd = G__open_misc(dir, element, name, G_mapset(), 2);
     if (fd < 0)
         return (FILE *)0;
-    lseek(fd, 0L, SEEK_END);
+    if (lseek(fd, 0L, SEEK_END) == -1) {
+        int err = errno;
+        G_warning(_("File read/write operation failed: %s (%d)"), strerror(err),
+                  err);
+        return (FILE *)-1;
+    }
 
     return fdopen(fd, "r+");
 }

lib/gis/seek.c

@@ -50,14 +50,20 @@ off_t G_ftell(FILE *fp)
 void G_fseek(FILE *fp, off_t offset, int whence)
 {
 #ifdef HAVE_FSEEKO
-    if (fseeko(fp, offset, whence) != 0)
-        G_fatal_error(_("Unable to seek: %s"), strerror(errno));
+    if (fseeko(fp, offset, whence) != 0) {
+        int err = errno;
+        G_fatal_error(_("File read/write operation failed: %s (%d)"),
+                      strerror(err), err);
+    }
 #else
     long loff = (long)offset;
 
     if ((off_t)loff != offset)
         G_fatal_error(_("Seek offset out of range"));
-    if (fseek(fp, loff, whence) != 0)
-        G_fatal_error(_("Unable to seek: %s"), strerror(errno));
+    if (fseek(fp, loff, whence) != 0) {
+        int err = errno;
+        G_fatal_error(_("File read/write operation failed: %s (%d)"),
+                      strerror(err), err);
+    }
 #endif
 }

lib/raster/close.c

@@ -396,6 +396,11 @@ static int close_new(int fd, int ok)
         if (fcb->null_row_ptr) { /* compressed nulls */
             fcb->null_row_ptr[fcb->cellhd.rows] =
                 lseek(fcb->null_fd, 0L, SEEK_CUR);
+            if (fcb->null_row_ptr[fcb->cellhd.rows] == -1) {
+                int err = errno;
+                G_fatal_error(_("File read/write operation failed: %s (%d)"),
+                              strerror(err), err);
+            }
             Rast__write_null_row_ptrs(fd, fcb->null_fd);
         }
 
@@ -437,6 +442,11 @@ static int close_new(int fd, int ok)
 
         if (fcb->open_mode == OPEN_NEW_COMPRESSED) { /* auto compression */
             fcb->row_ptr[fcb->cellhd.rows] = lseek(fcb->data_fd, 0L, SEEK_CUR);
+            if (fcb->row_ptr[fcb->cellhd.rows] == -1) {
+                int err = errno;
+                G_fatal_error(_("File read/write operation failed: %s (%d)"),
+                              strerror(err), err);
+            }
             Rast__write_row_ptrs(fd);
         }
 
@@ -531,6 +541,11 @@ void Rast__close_null(int fd)
 
     if (fcb->null_row_ptr) { /* compressed nulls */
         fcb->null_row_ptr[fcb->cellhd.rows] = lseek(fcb->null_fd, 0L, SEEK_CUR);
+        if (fcb->null_row_ptr[fcb->cellhd.rows] == -1) {
+            int err = errno;
+            G_fatal_error(_("File read/write operation failed: %s (%d)"),
+                          strerror(err), err);
+        }
         Rast__write_null_row_ptrs(fd, fcb->null_fd);
         G_free(fcb->null_row_ptr);
     }

lib/raster/format.c

@@ -190,7 +190,11 @@ static int write_row_ptrs(int nrows, off_t *row_ptr, int fd)
     unsigned char *buf, *b;
     int len, row, result;
 
-    lseek(fd, 0L, SEEK_SET);
+    if (lseek(fd, 0L, SEEK_SET) == -1) {
+        int err = errno;
+        G_fatal_error(_("File read/write operation failed: %s (%d)"),
+                      strerror(err), err);
+    }
 
     len = (nrows + 1) * nbytes + 1;
     b = buf = G_malloc(len);

lib/raster/get_row.c

@@ -93,7 +93,7 @@ static void read_data_fp_compressed(int fd, int row, unsigned char *data_buf,
     size_t bufsize = fcb->cellhd.cols * fcb->nbytes;
     int ret;
 
-    if (lseek(fcb->data_fd, t1, SEEK_SET) < 0)
+    if (lseek(fcb->data_fd, t1, SEEK_SET) == -1)
         G_fatal_error(
             _("Error seeking fp raster data file for row %d of <%s>: %s"), row,
             fcb->name, strerror(errno));
@@ -138,7 +138,7 @@ static void read_data_compressed(int fd, int row, unsigned char *data_buf,
     unsigned char *cmp, *cmp2;
     int n;
 
-    if (lseek(fcb->data_fd, t1, SEEK_SET) < 0)
+    if (lseek(fcb->data_fd, t1, SEEK_SET) == -1)
         G_fatal_error(
             _("Error seeking raster data file for row %d of <%s>: %s"), row,
             fcb->name, strerror(errno));
@@ -854,7 +854,7 @@ static int read_null_bits_compressed(int null_fd, unsigned char *flags, int row,
     unsigned char *compressed_buf;
     int res;
 
-    if (lseek(null_fd, t1, SEEK_SET) < 0)
+    if (lseek(null_fd, t1, SEEK_SET) == -1)
         G_fatal_error(
             _("Error seeking compressed null data for row %d of <%s>"), row,
             fcb->name);
@@ -914,7 +914,7 @@ int Rast__read_null_bits(int fd, int row, unsigned char *flags)
 
     offset = (off_t)size * R;
 
-    if (lseek(null_fd, offset, SEEK_SET) < 0)
+    if (lseek(null_fd, offset, SEEK_SET) == -1)
         G_fatal_error(_("Error seeking null row %d for <%s>"), R, fcb->name);
 
     if (read(null_fd, flags, size) != size)

lib/raster/put_row.c

@@ -140,6 +140,11 @@ static void set_file_pointer(int fd, int row)
     struct fileinfo *fcb = &R__.fileinfo[fd];
 
     fcb->row_ptr[row] = lseek(fcb->data_fd, 0L, SEEK_CUR);
+    if (fcb->row_ptr[row] == -1) {
+        int err = errno;
+        G_fatal_error(_("File read/write operation failed: %s (%d)"),
+                      strerror(err), err);
+    }
 }
 
 static void convert_float(float *work_buf, char *null_buf, const FCELL *rast,
@@ -514,6 +519,11 @@ static void write_null_bits_compressed(const unsigned char *flags, int row,
     int res;
 
     fcb->null_row_ptr[row] = lseek(fcb->null_fd, 0L, SEEK_CUR);
+    if (fcb->null_row_ptr[row] == -1) {
+        int err = errno;
+        G_fatal_error(_("File read/write operation failed: %s (%d)"),
+                      strerror(err), err);
+    }
 
     /* get upper bound of compressed size */
     cmax = G_compress_bound(size, 3);
@@ -567,7 +577,7 @@ void Rast__write_null_bits(int fd, const unsigned char *flags)
 
     offset = (off_t)size * row;
 
-    if (lseek(fcb->null_fd, offset, SEEK_SET) < 0)
+    if (lseek(fcb->null_fd, offset, SEEK_SET) == -1)
         G_fatal_error(_("Error writing null row %d of <%s>"), row, fcb->name);
 
     if ((res = write(fcb->null_fd, flags, size)) < 0 ||