var: add a '64dec' function that can base64 decode a string

Verified in test 455 and 487.

If the provided string cannot be base64-decoded, it will instead use
"[64dec-fail]" (without the quotes).

Documented

Ref: #16288
Closes #16330

tests/data/Makefile.am

@@ -78,7 +78,7 @@ test444 test445 test446 test447 test448 test449 test450 test451 test452 \
 test453 test454 test455 test456 test457 test458 test459 test460 test461 \
 test462 test463 test467 test468 test469 test470 test471 test472 test473 \
 test474 test475 test476 test477 test478 test479 test480 test481 test482 \
-test483 test484 test485 test486 \
+test483 test484 test485 test486 test487 \
 test490 test491 test492 test493 test494 test495 test496 test497 test498 \
 test499 test500 test501 test502 test503 test504 test505 test506 test507 \
 test508 test509 test510 test511 test512 test513 test514 test515 test516 \

tests/data/test455

@@ -34,7 +34,7 @@ http
 Variable using base64
 </name>
 <command>
---variable moby="Call me Ishmael" --expand-url "http://%HOSTIP:%HTTPPORT/{{moby:b64}}/%TESTNUMBER"
+--variable moby="Call me Ishmael" --variable what=%b64[white-whale]b64% --expand-url "http://%HOSTIP:%HTTPPORT/{{moby:b64}}/{{what:64dec}}/%TESTNUMBER"
 </command>
 </client>
 
@@ -42,7 +42,7 @@ Variable using base64
 # Verify data after the test has been "shot"
 <verify>
 <protocol crlf="yes">
-GET /%b64[Call me Ishmael]b64%/%TESTNUMBER HTTP/1.1
+GET /%b64[Call me Ishmael]b64%/white-whale/%TESTNUMBER HTTP/1.1
 Host: %HOSTIP:%HTTPPORT
 User-Agent: curl/%VERSION
 Accept: */*

tests/data/test487

@@ -0,0 +1,52 @@
+<testcase>
+<info>
+<keywords>
+variables
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<data crlf="yes">
+HTTP/1.1 200 OK
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Server: test-server/fake
+Last-Modified: Tue, 13 Jun 2000 12:10:00 GMT
+ETag: "21025-dc7-39462498"
+Accept-Ranges: bytes
+Content-Length: 6
+Connection: close
+Content-Type: text/html
+Funny-head: yesyes
+
+-foo-
+</data>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+http
+</server>
+<name>
+Variable using 64dec with bad base64
+</name>
+<command>
+--variable what=not-base64-data --expand-url "http://%HOSTIP:%HTTPPORT/{{what:64dec}}/%TESTNUMBER" -g
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<protocol crlf="yes">
+GET /[64dec-fail]/%TESTNUMBER HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+User-Agent: curl/%VERSION
+Accept: */*
+
+</protocol>
+</verify>
+</testcase>