Sorted loadfiles() results were corrupted when detail was < normal

When only reading the index (detail = file_detail_index), smb_getfile() just sets the file->name convenience pointer to point to the name in the index. Then when loadfiles() would sort the list, these pointers would not be adjusted (so they would point to the wrong names) resulting in a corrupted file list (e.g. name/size mismatches and no logical sort order).

The solution is to call smb_getfile() on each file *after* the read index records have been sorted.

This also means that the sort-by-name routines needed to always sort using the index name and not the convenience pointer (which is NULL in this case).

While fixing this, I noticed there was no bounds checking in the loadfiles() and loadfilenames() read-loops, so if the indexes happened to be longer than the total_files value from the status header, a buffer under-alloc/overflow would occur and a likely crash as a result. So stop reading the index when the expected maximum number of index records have been read.

src/sbbs3/filedat.c

@@ -155,12 +155,15 @@ str_list_t loadfilenames(smb_t* smb, const char* filespec, time_t t, enum file_s
 		return NULL;
 
 	fseek(smb->sid_fp, start * sizeof(fileidxrec_t), SEEK_SET);
-	while(!feof(smb->sid_fp)) {
+	size_t offset = start;
+	while(!feof(smb->sid_fp) && offset < smb->status.total_files) {
 		fileidxrec_t fidx;
 
 		if(smb_fread(smb, &fidx, sizeof(fidx), smb->sid_fp) != sizeof(fidx))
 			break;
 
+		offset++;
+
 		if(fidx.idx.number == 0)	/* invalid message number, ignore */
 			continue;
 
@@ -197,9 +200,10 @@ file_t* loadfiles(smb_t* smb, const char* filespec, time_t t, enum file_detail d
 		return NULL;
 
 	fseek(smb->sid_fp, start * sizeof(fileidxrec_t), SEEK_SET);
-	long offset = start;
-	while(!feof(smb->sid_fp)) {
-		file_t* f = &file_list[*count];
+	size_t offset = start;
+	size_t cnt = 0;
+	while(!feof(smb->sid_fp) && offset < smb->status.total_files) {
+		file_t* f = &file_list[cnt];
 
 		if(smb_fread(smb, &f->file_idx, sizeof(f->file_idx), smb->sid_fp) != sizeof(f->file_idx))
 			break;
@@ -215,14 +219,17 @@ file_t* loadfiles(smb_t* smb, const char* filespec, time_t t, enum file_detail d
 			if(!wildmatch(f->file_idx.name, filespec, /* path: */false, /* case-sensitive: */false))
 				continue;
 		}
-		int result = smb_getfile(smb, f, detail);
-		if(result != SMB_SUCCESS)
-			break;
-		(*count)++;
+		cnt++;
 	}
 	if(order != FILE_SORT_NATURAL)
-		sortfiles(file_list, *count, order);
+		sortfiles(file_list, cnt, order);
 
+	// Read (and set convenience pointers) *after* sorting the list
+	for((*count) = 0; (*count) < cnt; (*count)++) {
+		int result = smb_getfile(smb, &file_list[*count], detail);
+		if(result != SMB_SUCCESS)
+			break;
+	}
 	return file_list;
 }
 
@@ -231,7 +238,7 @@ static int file_compare_name_a(const void* v1, const void* v2)
 	file_t* f1 = (file_t*)v1;
 	file_t* f2 = (file_t*)v2;
 
-	return stricmp(f1->name, f2->name);
+	return stricmp(f1->file_idx.name, f2->file_idx.name);
 }
 
 static int file_compare_name_ac(const void* v1, const void* v2)
@@ -239,7 +246,7 @@ static int file_compare_name_ac(const void* v1, const void* v2)
 	file_t* f1 = (file_t*)v1;
 	file_t* f2 = (file_t*)v2;
 
-	return strcmp(f1->name, f2->name);
+	return strcmp(f1->file_idx.name, f2->file_idx.name);
 }
 
 static int file_compare_name_d(const void* v1, const void* v2)
@@ -247,7 +254,7 @@ static int file_compare_name_d(const void* v1, const void* v2)
 	file_t* f1 = (file_t*)v1;
 	file_t* f2 = (file_t*)v2;
 
-	return stricmp(f2->name, f1->name);
+	return stricmp(f2->file_idx.name, f1->file_idx.name);
 }
 
 static int file_compare_name_dc(const void* v1, const void* v2)
@@ -255,7 +262,7 @@ static int file_compare_name_dc(const void* v1, const void* v2)
 	file_t* f1 = (file_t*)v1;
 	file_t* f2 = (file_t*)v2;
 
-	return strcmp(f2->name, f1->name);
+	return strcmp(f2->file_idx.name, f1->file_idx.name);
 }
 
 static int file_compare_date_a(const void* v1, const void* v2)