JSON: add jsons extract variant, to strip quotes from string results

4 files changed, 35 insertions, 6 deletions

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index d21a71857..d762f9754 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -9412,6 +9412,8 @@ This forces an expansion failure (see section &<<SECTforexpfai>>&);
 .new
 .vitem "&*${extract json{*&<&'key'&>&*}{*&<&'string1'&>&*}{*&<&'string2'&>&*}&&&
        {*&<&'string3'&>&*}}*&"
+.vitem "&*${extract jsons{*&<&'key'&>&*}{*&<&'string1'&>&*}{*&<&'string2'&>&*}&&&
+       {*&<&'string3'&>&*}}*&"
 .cindex "expansion" "extracting from JSON object"
 .cindex JSON expansions
 The key and <&'string1'&> are first expanded separately. Leading and trailing
@@ -9425,8 +9427,11 @@ The expanded <&'string1'&> must be of the form:
 The braces, commas and colons, and the quoting of the member name are required;
 the spaces are optional.
 Matching of the key against the member names is done case-sensitively.
-If a returned value is a JSON string, it retains its leading and
+For the &"json"& variant,
+if a returned value is a JSON string, it retains its leading and
 trailing quotes.
+For the &"jsons"& variant, which is intended for use with JSON strings, the
+leading and trailing quotes are removed.
 . XXX should be a UTF-8 compare
 
 The results of matching are handled as above.
@@ -9467,6 +9472,8 @@ empty (for example, the fifth field above).
 .new
 .vitem "&*${extract json{*&<&'number'&>&*}}&&&
         {*&<&'string1'&>&*}{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*&"
+.vitem "&*${extract jsons{*&<&'number'&>&*}}&&&
+        {*&<&'string1'&>&*}{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*&"
 .cindex "expansion" "extracting from JSON array"
 .cindex JSON expansions
 The <&'number'&> argument must consist entirely of decimal digits,
@@ -9474,8 +9481,11 @@ apart from leading and trailing white space, which is ignored.
 
 Field selection and result handling is as above;
 there is no choice of field separator.
-If a returned value is a JSON string, it retains its leading and
+For the &"json"& variant,
+if a returned value is a JSON string, it retains its leading and
 trailing quotes.
+For the &"jsons"& variant, which is intended for use with JSON strings, the
+leading and trailing quotes are removed.
 .wen
 
 
diff --git a/src/src/expand.c b/src/src/expand.c
index 2f05737fc..679148726 100644
--- a/src/src/expand.c
+++ b/src/src/expand.c
@@ -5635,7 +5635,7 @@ while (*s != 0)
       uschar *sub[3];
       int save_expand_nmax =
         save_expand_strings(save_expand_nstring, save_expand_nlength);
-      enum {extract_basic, extract_json} fmt = extract_basic;
+      enum {extract_basic, extract_json, extract_jsons} fmt = extract_basic;
 
       while (isspace(*s)) s++;
 
@@ -5643,7 +5643,10 @@ while (*s != 0)
 
       if (*s != '{')					/*}*/
 	if (Ustrncmp(s, "json", 4) == 0)
-	  {fmt = extract_json; s += 4;}
+	  if (*(s += 4) == 's')
+	    {fmt = extract_jsons; s++;}
+	  else
+	    fmt = extract_json;
 
       /* While skipping we cannot rely on the data for expansions being
       available (eg. $item) hence cannot decide on numeric vs. keyed.
@@ -5724,7 +5727,7 @@ while (*s != 0)
 	    if (*p == 0)
 	      {
 	      field_number *= x;
-	      if (fmt != extract_json) j = 3;               /* Need 3 args */
+	      if (fmt == extract_basic) j = 3;               /* Need 3 args */
 	      field_number_set = TRUE;
 	      }
             }
@@ -5751,6 +5754,7 @@ while (*s != 0)
 	  break;
 
 	case extract_json:
+	case extract_jsons:
 	  {
 	  uschar * s, * item;
 	  const uschar * list;
@@ -5816,6 +5820,15 @@ while (*s != 0)
 	      }
 	    }
 	  }
+
+	  if (fmt == extract_jsons)
+	    if (!(lookup_value = dewrap(lookup_value, US"\"\"")))
+	      {
+	      expand_string_message =
+		string_sprintf("%s wrapping string result for extract jsons",
+		  expand_string_message);
+	      goto EXPAND_FAILED_CURLY;
+	      }
 	}
 
       /* If no string follows, $value gets substituted; otherwise there can
diff --git a/test/scripts/0000-Basic/0002 b/test/scripts/0000-Basic/0002
index 7a9b38dba..397445273 100644
--- a/test/scripts/0000-Basic/0002
+++ b/test/scripts/0000-Basic/0002
@@ -893,6 +893,9 @@ ${extract json {Width} \
 ${extract json {2} {[116, 943, 234, 38793]} }
 ${extract json {2} {${extract json{IDs} {\{"other":"foo", "IDs": [116, 943, 234]\} }}} }
 
+${extract json {2} {["red", "green", "blue", "black"]} }
+${extract jsons{2} {["red", "green", "blue", "black"]} }
+
 ${extract json {seconds} { \{"hours":0, "mins":0, "seconds":59\} }}
 ${extract json {seconds} {${extract json {2} { ["irrelevant", \{"hours":0, "mins":0, "seconds":59\}] }}}}
 
diff --git a/test/stdout/0002 b/test/stdout/0002
index 44117a9fc..dd54b16eb 100644
--- a/test/stdout/0002
+++ b/test/stdout/0002
@@ -836,6 +836,9 @@ xyz
 > 943
 > 943
 > 
+> "green"
+> green
+> 
 > 59
 > 59
 > 
@@ -845,7 +848,7 @@ xyz
 > {"1":116, "2":943, "3":234}
 > expect: {"1":116, "2":943, "3":234}
 > 
-> Failed: missing '"' wrapping string key for extract json
+> <>
 > expect: <>
 > 
 >