Check return values of some library calls.

4 files changed, 26 insertions, 6 deletions

diff --git a/lib-src/ChangeLog b/lib-src/ChangeLog
index 232bb389fd7..74509f4ae5e 100644
--- a/lib-src/ChangeLog
+++ b/lib-src/ChangeLog
@@ -1,3 +1,11 @@
+2011-01-23  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Check return values of some library calls.
+        * hexl.c (main): Check fread result.
+        * make-docfile.c (main): Check chdir result.
+        (scan_c_file): Check fscanf result.
+        * movemail.c (main): Check ftruncate result.
+
 2011-01-17  Paul Eggert  <eggert@cs.ucla.edu>
 
         Include <unistd.h> unilaterally.
diff --git a/lib-src/hexl.c b/lib-src/hexl.c
index aa5b370aade..e0a5166760a 100644
--- a/lib-src/hexl.c
+++ b/lib-src/hexl.c
@@ -179,7 +179,9 @@ main (int argc, char **argv)
 
 #define hexchar(x) (isdigit (x) ? x - '0' : x - 'a' + 10)
 
-              fread (buf, 1, 10, fp); /* skip 10 bytes */
+              /* Skip 10 bytes.  */
+              if (fread (buf, 1, 10, fp) != 10)
+                break;
 
               for (i=0; i < 16; ++i)
                 {
@@ -207,7 +209,9 @@ main (int argc, char **argv)
                   if (i < 16)
                     break;
 
-                  fread (buf, 1, 18, fp); /* skip 18 bytes */
+                  /* Skip 18 bytes.  */
+                  if (fread (buf, 1, 18, fp) != 18)
+                    break;
                 }
             }
         }
diff --git a/lib-src/make-docfile.c b/lib-src/make-docfile.c
index 4260e4c08f6..b6fccfacfec 100644
--- a/lib-src/make-docfile.c
+++ b/lib-src/make-docfile.c
@@ -158,7 +158,11 @@ main (int argc, char **argv)
     }
   if (argc > i + 1 && !strcmp (argv[i], "-d"))
     {
-      chdir (argv[i + 1]);
+      if (chdir (argv[i + 1]) != 0)
+        {
+          perror (argv[i + 1]);
+          return EXIT_FAILURE;
+        }
       i += 2;
     }
 
@@ -648,6 +652,7 @@ scan_c_file (char *filename, const char *mode)
 
               if (defunflag && (commas == 1 || commas == 2))
                 {
+                  int scanned = 0;
                   do
                     c = getc (infile);
                   while (c == ' ' || c == '\n' || c == '\r' || c == '\t');
@@ -655,12 +660,14 @@ scan_c_file (char *filename, const char *mode)
                     goto eof;
                   ungetc (c, infile);
                   if (commas == 2) /* pick up minargs */
-                    fscanf (infile, "%d", &minargs);
+                    scanned = fscanf (infile, "%d", &minargs);
                   else /* pick up maxargs */
                     if (c == 'M' || c == 'U') /* MANY || UNEVALLED */
                       maxargs = -1;
                     else
-                      fscanf (infile, "%d", &maxargs);
+                      scanned = fscanf (infile, "%d", &maxargs);
+                  if (scanned < 0)
+                    goto eof;
                 }
             }
 
diff --git a/lib-src/movemail.c b/lib-src/movemail.c
index b127c85951d..f492188963d 100644
--- a/lib-src/movemail.c
+++ b/lib-src/movemail.c
@@ -488,7 +488,8 @@ main (int argc, char **argv)
 #ifdef MAIL_USE_SYSTEM_LOCK
       if (! preserve_mail)
         {
-          ftruncate (indesc, 0L);
+          if (ftruncate (indesc, 0L) != 0)
+            pfatal_with_name (inname);
         }
 #endif /* MAIL_USE_SYSTEM_LOCK */