cmd/pprof: fix exception when file or path contains colon

Fixes #63924

Change-Id: I4ea17979faaca04eb6b046abffca2dd77397e0cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/539595
Reviewed-by: Cherry Mui <[email protected]>
Reviewed-by: David Chase <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Run-TryBot: shuang cui <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>

Author: cuishuang

src/cmd/pprof/pprof.go

@@ -45,6 +45,16 @@ type fetcher struct {
 }
 
 func (f *fetcher) Fetch(src string, duration, timeout time.Duration) (*profile.Profile, string, error) {
+	// Firstly, determine if the src is an existing file on the disk.
+	// If it is a file, let regular pprof open it.
+	// If it is not a file, when the src contains `:`
+	// (e.g. mem_2023-11-02_03:55:24 or abc:123/mem_2023-11-02_03:55:24),
+	// url.Parse will recognize it as a link and ultimately report an error,
+	// similar to `abc:123/mem_2023-11-02_03:55:24:
+	// Get "http://abc:123/mem_2023-11-02_03:55:24": dial tcp: lookup abc: no such host`
+	if _, openErr := os.Stat(src); openErr == nil {
+		return nil, "", nil
+	}
 	sourceURL, timeout := adjustURL(src, duration, timeout)
 	if sourceURL == "" {
 		// Could not recognize URL, let regular pprof attempt to fetch the profile (eg. from a file)