short i/o: fix config updates to use write_in_full

We need to check that the writes we perform during the update of
the users configuration work.  Convert to using write_in_full().

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/config.c b/config.c
index 5cbd130be2664258b488d8b4ca914550e10906a0..9ded954496af7698ef46fb971c69e4b01e2e9db3 100644 (file)
--- a/config.c
+++ b/config.c
@@ -464,7 +464,15 @@ static int store_aux(const char* key, const char* value)
        return 0;
 }
 
-static void store_write_section(int fd, const char* key)
+static int write_error()
+{
+       fprintf(stderr, "Failed to write new configuration file\n");
+
+       /* Same error code as "failed to rename". */
+       return 4;
+}
+
+static int store_write_section(int fd, const char* key)
 {
        const char *dot = strchr(key, '.');
        int len1 = store.baselen, len2 = -1;
@@ -478,37 +486,60 @@ static void store_write_section(int fd, const char* key)
                }
        }
 
-       write(fd, "[", 1);
-       write(fd, key, len1);
+       if (write_in_full(fd, "[", 1) != 1 ||
+           write_in_full(fd, key, len1) != len1)
+               return 0;
        if (len2 >= 0) {
-               write(fd, " \"", 2);
+               if (write_in_full(fd, " \"", 2) != 2)
+                       return 0;
                while (--len2 >= 0) {
                        unsigned char c = *++dot;
                        if (c == '"')
-                               write(fd, "\\", 1);
-                       write(fd, &c, 1);
+                               if (write_in_full(fd, "\\", 1) != 1)
+                                       return 0;
+                       if (write_in_full(fd, &c, 1) != 1)
+                               return 0;
                }
-               write(fd, "\"", 1);
+               if (write_in_full(fd, "\"", 1) != 1)
+                       return 0;
        }
-       write(fd, "]\n", 2);
+       if (write_in_full(fd, "]\n", 2) != 2)
+               return 0;
+
+       return 1;
 }
 
-static void store_write_pair(int fd, const char* key, const char* value)
+static int store_write_pair(int fd, const char* key, const char* value)
 {
        int i;
+       int length = strlen(key+store.baselen+1);
 
-       write(fd, "\t", 1);
-       write(fd, key+store.baselen+1,
-               strlen(key+store.baselen+1));
-       write(fd, " = ", 3);
+       if (write_in_full(fd, "\t", 1) != 1 ||
+           write_in_full(fd, key+store.baselen+1, length) != length ||
+           write_in_full(fd, " = ", 3) != 3)
+               return 0;
        for (i = 0; value[i]; i++)
                switch (value[i]) {
-               case '\n': write(fd, "\\n", 2); break;
-               case '\t': write(fd, "\\t", 2); break;
-               case '"': case '\\': write(fd, "\\", 1);
-               default: write(fd, value+i, 1);
-       }
-       write(fd, "\n", 1);
+               case '\n':
+                       if (write_in_full(fd, "\\n", 2) != 2)
+                               return 0;
+                       break;
+               case '\t':
+                       if (write_in_full(fd, "\\t", 2) != 2)
+                               return 0;
+                       break;
+               case '"':
+               case '\\':
+                       if (write_in_full(fd, "\\", 1) != 1)
+                               return 0;
+               default:
+                       if (write_in_full(fd, value+i, 1) != 1)
+                               return 0;
+                       break;
+               }
+       if (write_in_full(fd, "\n", 1) != 1)
+               return 0;
+       return 1;
 }
 
 static int find_beginning_of_line(const char* contents, int size,
@@ -648,8 +679,11 @@ int git_config_set_multivar(const char* key, const char* value,
                }
 
                store.key = (char*)key;
-               store_write_section(fd, key);
-               store_write_pair(fd, key, value);
+               if (!store_write_section(fd, key) ||
+                   !store_write_pair(fd, key, value)) {
+                       ret = write_error();
+                       goto out_free;
+               }
        } else{
                struct stat st;
                char* contents;
@@ -729,10 +763,10 @@ int git_config_set_multivar(const char* key, const char* value,
 
                        /* write the first part of the config */
                        if (copy_end > copy_begin) {
-                               write(fd, contents + copy_begin,
+                               write_in_full(fd, contents + copy_begin,
                                copy_end - copy_begin);
                                if (new_line)
-                                       write(fd, "\n", 1);
+                                       write_in_full(fd, "\n", 1);
                        }
                        copy_begin = store.offset[i];
                }
@@ -740,13 +774,19 @@ int git_config_set_multivar(const char* key, const char* value,
                /* write the pair (value == NULL means unset) */
                if (value != NULL) {
                        if (store.state == START)
-                               store_write_section(fd, key);
-                       store_write_pair(fd, key, value);
+                               if (!store_write_section(fd, key)) {
+                                       ret = write_error();
+                                       goto out_free;
+                               }
+                       if (!store_write_pair(fd, key, value)) {
+                               ret = write_error();
+                               goto out_free;
+                       }
                }
 
                /* write the rest of the config */
                if (copy_begin < st.st_size)
-                       write(fd, contents + copy_begin,
+                       write_in_full(fd, contents + copy_begin,
                                st.st_size - copy_begin);
 
                munmap(contents, st.st_size);
@@ -800,6 +840,7 @@ int git_config_rename_section(const char *old_name, const char *new_name)
 
        while (fgets(buf, sizeof(buf), config_file)) {
                int i;
+               int length;
                for (i = 0; buf[i] && isspace(buf[i]); i++)
                        ; /* do nothing */
                if (buf[i] == '[') {
@@ -830,15 +871,22 @@ int git_config_rename_section(const char *old_name, const char *new_name)
                                /* old_name matches */
                                ret++;
                                store.baselen = strlen(new_name);
-                               store_write_section(out_fd, new_name);
+                               if (!store_write_section(out_fd, new_name)) {
+                                       ret = write_error();
+                                       goto out;
+                               }
                                continue;
                        }
                }
-               write(out_fd, buf, strlen(buf));
+               length = strlen(buf);
+               if (write_in_full(out_fd, buf, length) != length) {
+                       ret = write_error();
+                       goto out;
+               }
        }
        fclose(config_file);
        if (close(out_fd) || commit_lock_file(lock) < 0)
-               ret = error("Cannot commit config file!");
+                       ret = error("Cannot commit config file!");
  out:
        free(config_filename);
        return ret;