From: Patrick Monnerat <patrick@monnerat.net>
Date: Tue, 4 Oct 2022 14:50:45 +0000 (+0200)
Subject: tool: avoid generating ambiguous escaped characters in --libcurl
X-Git-Tag: curl-7_86_0~118
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=172259c4de33036e231748205eaa61087d1b9de4;p=thirdparty%2Fcurl.git

tool: avoid generating ambiguous escaped characters in --libcurl

C string hexadecimal-escaped characters may have more than 2 digits.
This results in a wrong C compiler interpretation of a 2-digit escaped
character when followed by an hex digit character.

The solution retained here is to represent such characters as 3-digit
octal escapes.

Adjust and extend test 1465 for this case.

Closes #9643
---

diff --git a/src/tool_setopt.c b/src/tool_setopt.c
index b051388895..917191ef29 100644
--- a/src/tool_setopt.c
+++ b/src/tool_setopt.c
@@ -252,12 +252,17 @@ static char *c_escape(const char *str, curl_off_t len)
       strcpy(e, "\\?");
       e += 2;
     }
-    else if(!ISPRINT(c)) {
+    else if(ISPRINT(c))
+      *e++ = c;
+    else if(len > 1 && ISXDIGIT(s[1])) {
+      /* Octal escape to avoid >2 digit hex. */
+      msnprintf(e, 5, "\\%03o", (unsigned)c);
+      e += 4;
+    }
+    else {
       msnprintf(e, 5, "\\x%02x", (unsigned)c);
       e += 4;
     }
-    else
-      *e++ = c;
   }
   while(cutoff--)
     *e++ = '.';
diff --git a/tests/data/test1465 b/tests/data/test1465
index 356b1e1b94..9703f68cf2 100644
Binary files a/tests/data/test1465 and b/tests/data/test1465 differ