General ref log reading improvements.

diff --git a/refs.c b/refs.c
index ae9825deadeda63c7ebc2d775ad59bd66256a6a4..9d37a028c3aabeefe06095e03be72a071ff66740 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -432,11 +432,12 @@ int write_ref_sha1(struct ref_lock *lock,
 
 int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1)
 {
-       const char *logfile, *logdata, *logend, *rec, *c;
+       const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
        char *tz_c;
        int logfd, tz;
        struct stat st;
        unsigned long date;
+       unsigned char logged_sha1[20];
 
        logfile = git_path("logs/%s", ref);
        logfd = open(logfile, O_RDONLY, 0);
@@ -448,32 +449,57 @@ int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1)
        logdata = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, logfd, 0);
        close(logfd);
 
+       lastrec = NULL;
        rec = logend = logdata + st.st_size;
        while (logdata < rec) {
                if (logdata < rec && *(rec-1) == '\n')
                        rec--;
-               while (logdata < rec && *(rec-1) != '\n')
+               lastgt = NULL;
+               while (logdata < rec && *(rec-1) != '\n') {
                        rec--;
-               c = rec;
-               while (c < logend && *c != '>' && *c != '\n')
-                       c++;
-               if (c == logend || *c == '\n')
+                       if (*rec == '>')
+                               lastgt = rec;
+               }
+               if (!lastgt)
                        die("Log %s is corrupt.", logfile);
-               date = strtoul(c + 1, NULL, 10);
+               date = strtoul(lastgt + 1, &tz_c, 10);
                if (date <= at_time) {
-                       if (get_sha1_hex(rec + 41, sha1))
-                               die("Log %s is corrupt.", logfile);
+                       if (lastrec) {
+                               if (get_sha1_hex(lastrec, logged_sha1))
+                                       die("Log %s is corrupt.", logfile);
+                               if (get_sha1_hex(rec + 41, sha1))
+                                       die("Log %s is corrupt.", logfile);
+                               if (memcmp(logged_sha1, sha1, 20)) {
+                                       tz = strtoul(tz_c, NULL, 10);
+                                       fprintf(stderr,
+                                               "warning: Log %s has gap after %s.\n",
+                                               logfile, show_rfc2822_date(date, tz));
+                               }
+                       } else if (date == at_time) {
+                               if (get_sha1_hex(rec + 41, sha1))
+                                       die("Log %s is corrupt.", logfile);
+                       } else {
+                               if (get_sha1_hex(rec + 41, logged_sha1))
+                                       die("Log %s is corrupt.", logfile);
+                               if (memcmp(logged_sha1, sha1, 20)) {
+                                       tz = strtoul(tz_c, NULL, 10);
+                                       fprintf(stderr,
+                                               "warning: Log %s unexpectedly ended on %s.\n",
+                                               logfile, show_rfc2822_date(date, tz));
+                               }
+                       }
                        munmap((void*)logdata, st.st_size);
                        return 0;
                }
+               lastrec = rec;
        }
 
-       c = logdata;
-       while (c < logend && *c != '>' && *c != '\n')
-               c++;
-       if (c == logend || *c == '\n')
+       rec = logdata;
+       while (rec < logend && *rec != '>' && *rec != '\n')
+               rec++;
+       if (rec == logend || *rec == '\n')
                die("Log %s is corrupt.", logfile);
-       date = strtoul(c, &tz_c, 10);
+       date = strtoul(rec + 1, &tz_c, 10);
        tz = strtoul(tz_c, NULL, 10);
        if (get_sha1_hex(logdata, sha1))
                die("Log %s is corrupt.", logfile);