Handle case where IDs file is out of sync with tsm1 file or missing

Avoids a panic if a series ID exists in the tsm file but not in the IDs file.
Also handles the case were we don't have an ids file and just a tsm file.

cmd/influx_inspect/tsm.go

@@ -212,6 +212,8 @@ func readIndex(f *os.File) *tsmIndex {
 }
 
 func dumpTsm1(path string) {
+	var errors []error
+
 	f, err := os.Open(path)
 	if err != nil {
 		println(err.Error())
@@ -266,12 +268,32 @@ func dumpTsm1(path string) {
 		key := invIds[block.id]
 		split := strings.Split(key, "#!~#")
 
+		// We dont' know know if we have fields so use an informative default
+		var measurement, field string = "UNKNOWN", "UNKNOWN"
+
+		// We read some IDs from the ids file
+		if len(invIds) > 0 {
+			// Change the default to error until we know we have a valid key
+			measurement = "ERR"
+			field = "ERR"
+
+			// Possible corruption? Try to read as much as we can and point to the problem.
+			if key == "" {
+				errors = append(errors, fmt.Errorf("index pos %d, field id: %d, missing key for id.", i, block.id))
+			} else if len(split) < 2 {
+				errors = append(errors, fmt.Errorf("index pos %d, field id: %d, key corrupt: got '%v'", i, block.id, key))
+			} else {
+				measurement = split[0]
+				field = split[1]
+			}
+		}
+
 		fmt.Fprintln(tw, "  "+strings.Join([]string{
 			strconv.FormatInt(int64(i), 10),
 			strconv.FormatUint(block.id, 10),
 			strconv.FormatInt(int64(block.offset), 10),
-			split[0],
-			split[1],
+			measurement,
+			field,
 		}, "\t"))
 
 	}
@@ -375,5 +397,12 @@ func dumpTsm1(path string) {
 	fmt.Printf("    Per block: %0.2f bytes/point\n", float64(blockSize)/float64(pointCount))
 	fmt.Printf("    Total: %0.2f bytes/point\n", float64(stat.Size())/float64(pointCount))
 
-	println()
+	if len(errors) > 0 {
+		println()
+		fmt.Printf("Errors (%d):\n", len(errors))
+		for _, err := range errors {
+			fmt.Printf("  * %v\n", err)
+		}
+		println()
+	}
 }