maint(): don't truncate the .sid and .hash files to 0-bytes before writing their

new contents,
Instead truncate to the new length after writing the new contents. This should
make the files more tolerant of "out of disk space" situations and reduce
the risk of lost data (0-byte files) due to low/no free disk space.

src/sbbs3/smbutil.c

@@ -708,9 +708,10 @@ void maint(void)
 				hash_t*	hashes = malloc(max_hashes * SMB_HASH_SOURCE_TYPES * sizeof(hash_t));
 				if(hashes != NULL) {
 					if(fread(hashes, sizeof(hash_t), max_hashes * SMB_HASH_SOURCE_TYPES, smb.hash_fp) == max_hashes * SMB_HASH_SOURCE_TYPES) {
-						CHSIZE_FP(smb.hash_fp,0);
 						rewind(smb.hash_fp);
 						fwrite(hashes, sizeof(hash_t), max_hashes * SMB_HASH_SOURCE_TYPES, smb.hash_fp);
+						fflush(smb.hash_fp);
+						CHSIZE_FP(smb.hash_fp, sizeof(hash_t) * max_hashes * SMB_HASH_SOURCE_TYPES);
 					}
 					free(hashes);
 				}
@@ -860,15 +861,16 @@ void maint(void)
 
 	printf("Re-writing index...\n");
 	rewind(smb.sid_fp);
-	CHSIZE_FP(smb.sid_fp,0);
 	for(m=n=0;m<l;m++) {
 		if(idx[m].attr&MSG_DELETE)
 			continue;
-		printf("%lu of %lu\r",++n,l-flagged);
+		n++;
+		printf("%lu of %lu\r", n, l-flagged);
 		fwrite(&idx[m],sizeof(idxrec_t),1,smb.sid_fp); 
 	}
-	printf("\nDone.\n\n");
 	fflush(smb.sid_fp);
+	CHSIZE_FP(smb.sid_fp, n * sizeof(idxrec_t));
+	printf("\nDone.\n\n");
 
 	free(idx);
 	smb.status.total_msgs-=flagged;