fix: improve error handling and fix bugs (#2499)

* code quality: improve error handling and fix bugs

- Fix bug: return err instead of closeErr in DecodeData error path (httpx.go)
- Improve error handling for strconv.Atoi calls in multiple locations
- Change hammingDistanceThreshold from var to const since it's never modified
- Fix redundant return statement in ListFilesWithPattern
- Improve port parsing to handle empty port strings explicitly

* runner: keep input counters incrementing under -skip-dedupe

Revert the defensive strconv.Atoi guard around the SkipDedupe branches:
values stored in r.hm are always integer strings written by this same
code path, so the parseErr/cnt>0 check is unreachable in practice, and
when taken literally it skipped the numHosts/numTargets increment for
duplicate inputs.

---------

Co-authored-by: Mzack9999 <mzack9999@protonmail.com>

common/fileutil/fileutil.go

@@ -52,7 +52,7 @@ func ListFilesWithPattern(rootpattern string) ([]string, error) {
 	if len(files) == 0 {
 		return nil, errors.New("no files found")
 	}
-	return files, err
+	return files, nil
 }
 
 // FileNameIsGlob check if the filanem is a pattern

common/hashes/jarm/jarmhash.go

@@ -75,8 +75,11 @@ func Jarm(dialer *fastdialer.Dialer, host string, duration int) string {
 			return ""
 		}
 		t.Host = u.Hostname()
-		port, _ := strconv.Atoi(u.Port())
-		t.Port = port
+		if portStr := u.Port(); portStr != "" {
+			if p, err := strconv.Atoi(portStr); err == nil {
+				t.Port = p
+			}
+		}
 	}
 	if t.Port == 0 {
 		t.Port = defaultPort

common/httpx/httpx.go

@@ -293,7 +293,7 @@ get_response:
 
 	respbody, err = DecodeData(respbody, httpresp.Header)
 	if err != nil && !shouldIgnoreBodyErrors {
-		return nil, closeErr
+		return nil, err
 	}
 
 	respbodystr := string(respbody)
@@ -307,8 +307,9 @@ get_response:
 	if resp.ContentLength <= 0 {
 		// check if it's in the header and convert to int
 		if contentLength, ok := resp.Headers["Content-Length"]; ok && len(contentLength) > 0 {
-			contentLengthInt, _ := strconv.Atoi(contentLength[0])
-			resp.ContentLength = contentLengthInt
+			if contentLengthInt, err := strconv.Atoi(contentLength[0]); err == nil {
+				resp.ContentLength = contentLengthInt
+			}
 		}
 
 		// if we have a body, then use the number of bytes in the body if the length is still zero

runner/runner.go

@@ -125,7 +125,7 @@ func (r *Runner) IsInterrupted() bool {
 }
 
 // picked based on try-fail but it seems to close to one it's used https://www.hackerfactor.com/blog/index.php?/archives/432-Looks-Like-It.html#c1992
-var hammingDistanceThreshold int = 22
+const hammingDistanceThreshold = 22
 
 // regex for stripping ANSI codes
 var ansiRegex = regexp.MustCompile(`\x1b\[[0-9;]*m`)
@@ -2204,7 +2204,12 @@ retry:
 
 	pipeline := false
 	if scanopts.Pipeline {
-		port, _ := strconv.Atoi(URL.Port())
+		port := 0
+		if portStr := URL.Port(); portStr != "" {
+			if p, err := strconv.Atoi(portStr); err == nil {
+				port = p
+			}
+		}
 		r.ratelimiter.Take()
 		pipeline = hp.SupportPipeline(protocol, method, URL.Host, port)
 		if pipeline {