Use tor_fgets() instead of fgets().

This patch changes our use of fgets() to tor_fgets() for more consistent
error handling across different versions of the C library.

src/common/util.c

@@ -5020,7 +5020,7 @@ tor_read_all_handle(FILE *h, char *buf, size_t count,
 
   while (numread != count) {
     /* Use fgets because that is what we use in log_from_pipe() */
-    retval = fgets(buf+numread, (int)(count-numread), h);
+    retval = tor_fgets(buf+numread, (int)(count-numread), h);
     if (NULL == retval) {
       if (feof(h)) {
         log_debug(LD_GENERAL, "fgets() reached end of file");
@@ -5355,7 +5355,7 @@ get_string_from_pipe(FILE *stream, char *buf_out, size_t count)
 
   tor_assert(count <= INT_MAX);
 
-  retval = fgets(buf_out, (int)count, stream);
+  retval = tor_fgets(buf_out, (int)count, stream);
 
   if (!retval) {
     if (feof(stream)) {

src/or/dirserv.c

@@ -2701,7 +2701,7 @@ dirserv_read_measured_bandwidths(const char *from_file,
     return -1;
   }
 
-  if (!fgets(line, sizeof(line), fp)
+  if (!tor_fgets(line, sizeof(line), fp)
           || !strlen(line) || line[strlen(line)-1] != '\n') {
     log_warn(LD_DIRSERV, "Long or truncated time in bandwidth file: %s",
              escaped(line));
@@ -2731,7 +2731,7 @@ dirserv_read_measured_bandwidths(const char *from_file,
 
   while (!feof(fp)) {
     measured_bw_line_t parsed_line;
-    if (fgets(line, sizeof(line), fp) && strlen(line)) {
+    if (tor_fgets(line, sizeof(line), fp) && strlen(line)) {
       if (measured_bw_line_parse(&parsed_line, line) != -1) {
         /* Also cache the line for dirserv_get_bandwidth_for_router() */
         dirserv_cache_measured_bw(&parsed_line, file_time);

src/or/geoip.c

@@ -346,7 +346,7 @@ geoip_load_file(sa_family_t family, const char *filename)
              (family == AF_INET) ? "IPv4" : "IPv6", filename);
   while (!feof(f)) {
     char buf[512];
-    if (fgets(buf, (int)sizeof(buf), f) == NULL)
+    if (tor_fgets(buf, (int)sizeof(buf), f) == NULL)
       break;
     crypto_digest_add_bytes(geoip_digest_env, buf, strlen(buf));
     /* FFFF track full country name. */

src/test/test_util.c

@@ -3972,16 +3972,16 @@ test_util_fgets_eagain(void *ptr)
   /* Send in a partial line */
   retlen = write(test_pipe[1], "A", 1);
   tt_int_op(retlen, OP_EQ, 1);
-  retptr = fgets(buf, sizeof(buf), test_stream);
+  retptr = tor_fgets(buf, sizeof(buf), test_stream);
   tt_int_op(errno, OP_EQ, EAGAIN);
-  tt_ptr_op(retptr, OP_EQ, buf);
+  tt_ptr_op(retptr, OP_EQ, NULL);
   tt_str_op(buf, OP_EQ, "A");
   errno = 0;
 
   /* Send in the rest */
   retlen = write(test_pipe[1], "B\n", 2);
   tt_int_op(retlen, OP_EQ, 2);
-  retptr = fgets(buf, sizeof(buf), test_stream);
+  retptr = tor_fgets(buf, sizeof(buf), test_stream);
   tt_int_op(errno, OP_EQ, 0);
   tt_ptr_op(retptr, OP_EQ, buf);
   tt_str_op(buf, OP_EQ, "B\n");
@@ -3990,7 +3990,7 @@ test_util_fgets_eagain(void *ptr)
   /* Send in a full line */
   retlen = write(test_pipe[1], "CD\n", 3);
   tt_int_op(retlen, OP_EQ, 3);
-  retptr = fgets(buf, sizeof(buf), test_stream);
+  retptr = tor_fgets(buf, sizeof(buf), test_stream);
   tt_int_op(errno, OP_EQ, 0);
   tt_ptr_op(retptr, OP_EQ, buf);
   tt_str_op(buf, OP_EQ, "CD\n");
@@ -3999,16 +3999,16 @@ test_util_fgets_eagain(void *ptr)
   /* Send in a partial line */
   retlen = write(test_pipe[1], "E", 1);
   tt_int_op(retlen, OP_EQ, 1);
-  retptr = fgets(buf, sizeof(buf), test_stream);
+  retptr = tor_fgets(buf, sizeof(buf), test_stream);
   tt_int_op(errno, OP_EQ, EAGAIN);
-  tt_ptr_op(retptr, OP_EQ, buf);
+  tt_ptr_op(retptr, OP_EQ, NULL);
   tt_str_op(buf, OP_EQ, "E");
   errno = 0;
 
   /* Send in the rest */
   retlen = write(test_pipe[1], "F\n", 2);
   tt_int_op(retlen, OP_EQ, 2);
-  retptr = fgets(buf, sizeof(buf), test_stream);
+  retptr = tor_fgets(buf, sizeof(buf), test_stream);
   tt_int_op(errno, OP_EQ, 0);
   tt_ptr_op(retptr, OP_EQ, buf);
   tt_str_op(buf, OP_EQ, "F\n");
@@ -4020,14 +4020,14 @@ test_util_fgets_eagain(void *ptr)
   retval = close(test_pipe[1]);
   tt_int_op(retval, OP_EQ, 0);
   test_pipe[1] = -1;
-  retptr = fgets(buf, sizeof(buf), test_stream);
+  retptr = tor_fgets(buf, sizeof(buf), test_stream);
   tt_int_op(errno, OP_EQ, 0);
   tt_ptr_op(retptr, OP_EQ, buf);
   tt_str_op(buf, OP_EQ, "GH");
   errno = 0;
 
   /* Check for EOF */
-  retptr = fgets(buf, sizeof(buf), test_stream);
+  retptr = tor_fgets(buf, sizeof(buf), test_stream);
   tt_int_op(errno, OP_EQ, 0);
   tt_ptr_op(retptr, OP_EQ, NULL);
   retval = feof(test_stream);