Allow control characters in JSON5 string literals.

[forum:/forumpost/05182119f69c3a92|Forum thread 05182119f69c3a92].

FossilOrigin-Name: 34709c7cc910539e23a830ad8b589a97a88be25e924a59670c1017fb51447dad

1 files changed, 51 insertions, 27 deletions

diff --git a/src/json.c b/src/json.c
index 8f8196bd7..d58518990 100644
--- a/src/json.c
+++ b/src/json.c
@@ -621,6 +621,40 @@ static void jsonAppendSeparator(JsonString *p){
   jsonAppendChar(p, ',');
 }
 
+/* c is a control character.  Append the canonical JSON representation
+** of that control character to p.
+**
+** This routine assumes that the output buffer has already been enlarged
+** sufficiently to hold the worst-case encoding plus a nul terminator.
+*/
+static void jsonAppendControlChar(JsonString *p, u8 c){
+  static const char aSpecial[] = {
+     0, 0, 0, 0, 0, 0, 0, 0, 'b', 't', 'n', 0, 'f', 'r', 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0,   0,   0,   0, 0,   0,   0, 0, 0
+  };
+  assert( sizeof(aSpecial)==32 );
+  assert( aSpecial['\b']=='b' );
+  assert( aSpecial['\f']=='f' );
+  assert( aSpecial['\n']=='n' );
+  assert( aSpecial['\r']=='r' );
+  assert( aSpecial['\t']=='t' );
+  assert( c>=0 && c<sizeof(aSpecial) );
+  assert( p->nUsed+7 <= p->nAlloc );
+  if( aSpecial[c] ){
+    p->zBuf[p->nUsed] = '\\';
+    p->zBuf[p->nUsed+1] = aSpecial[c];
+    p->nUsed += 2;
+  }else{
+    p->zBuf[p->nUsed] = '\\';
+    p->zBuf[p->nUsed+1] = 'u';
+    p->zBuf[p->nUsed+2] = '0';
+    p->zBuf[p->nUsed+3] = '0';
+    p->zBuf[p->nUsed+4] = "0123456789abcdef"[c>>4];
+    p->zBuf[p->nUsed+5] = "0123456789abcdef"[c&0xf];
+    p->nUsed += 6;
+  }
+}
+
 /* Append the N-byte string in zIn to the end of the JsonString string
 ** under construction.  Enclose the string in double-quotes ("...") and
 ** escape any double-quotes or backslash characters contained within the
@@ -680,35 +714,14 @@ static void jsonAppendString(JsonString *p, const char *zIn, u32 N){
     }
     c = z[0];
     if( c=='"' || c=='\\' ){
-      json_simple_escape:
       if( (p->nUsed+N+3 > p->nAlloc) && jsonStringGrow(p,N+3)!=0 ) return;
       p->zBuf[p->nUsed++] = '\\';
       p->zBuf[p->nUsed++] = c;
     }else if( c=='\'' ){
       p->zBuf[p->nUsed++] = c;
     }else{
-      static const char aSpecial[] = {
-         0, 0, 0, 0, 0, 0, 0, 0, 'b', 't', 'n', 0, 'f', 'r', 0, 0,
-         0, 0, 0, 0, 0, 0, 0, 0,   0,   0,   0, 0,   0,   0, 0, 0
-      };
-      assert( sizeof(aSpecial)==32 );
-      assert( aSpecial['\b']=='b' );
-      assert( aSpecial['\f']=='f' );
-      assert( aSpecial['\n']=='n' );
-      assert( aSpecial['\r']=='r' );
-      assert( aSpecial['\t']=='t' );
-      assert( c>=0 && c<sizeof(aSpecial) );
-      if( aSpecial[c] ){
-        c = aSpecial[c];
-        goto json_simple_escape;
-      }
       if( (p->nUsed+N+7 > p->nAlloc) && jsonStringGrow(p,N+7)!=0 ) return;
-      p->zBuf[p->nUsed++] = '\\';
-      p->zBuf[p->nUsed++] = 'u';
-      p->zBuf[p->nUsed++] = '0';
-      p->zBuf[p->nUsed++] = '0';
-      p->zBuf[p->nUsed++] = "0123456789abcdef"[c>>4];
-      p->zBuf[p->nUsed++] = "0123456789abcdef"[c&0xf];
+      jsonAppendControlChar(p, c);
     }
     z++;
     N--;
@@ -1409,6 +1422,9 @@ static u32 jsonbValidityCheck(
         if( !jsonIsOk[z[j]] && z[j]!='\'' ){
           if( z[j]=='"' ){
             if( x==JSONB_TEXTJ ) return j+1;
+          }else if( z[j]<=0x1f ){
+            /* Control characters in JSON5 string literals are ok */
+            if( x==JSONB_TEXTJ ) return j+1;
           }else if( z[j]!='\\' || j+1>=k ){
             return j+1;
           }else if( strchr("\"\\/bfnrt",z[j+1])!=0 ){
@@ -1703,9 +1719,10 @@ json_parse_restart:
           return -1;
         }
       }else if( c<=0x1f ){
-        /* Control characters are not allowed in strings */
-        pParse->iErr = j;
-        return -1;
+        /* Control characters are not allowed in canonical JSON string
+        ** literals, but are allowed in JSON5 string literals. */
+        opcode = JSONB_TEXT5;
+        pParse->hasNonstd = 1;
       }else if( c=='"' ){
         opcode = JSONB_TEXT5;
       }
@@ -2186,7 +2203,7 @@ static u32 jsonTranslateBlobToText(
       zIn = (const char*)&pParse->aBlob[i+n];
       jsonAppendChar(pOut, '"');
       while( sz2>0 ){
-        for(k=0; k<sz2 && zIn[k]!='\\' && zIn[k]!='"'; k++){}
+        for(k=0; k<sz2 && (jsonIsOk[(u8)zIn[k]] || zIn[k]=='\''); k++){}
         if( k>0 ){
           jsonAppendRawNZ(pOut, zIn, k);
           if( k>=sz2 ){
@@ -2201,6 +2218,13 @@ static u32 jsonTranslateBlobToText(
           sz2--;
           continue;
         }
+        if( zIn[0]<=0x1f ){
+          if( pOut->nUsed+7<pOut->nAlloc && jsonStringGrow(pOut,7) ) break;
+          jsonAppendControlChar(pOut, zIn[0]);
+          zIn++;
+          sz2--;
+          continue;
+        }
         assert( zIn[0]=='\\' );
         assert( sz2>=1 );
         if( sz2<2 ){
@@ -4391,7 +4415,7 @@ static void jsonErrorFunc(
         /* Convert byte-offset s.iErr into a character offset */
         u32 k;
         assert( s.zJson!=0 );  /* Because s.oom is false */
-        for(k=0; k<s.iErr && ALWAYS(s.zJson[k]); k++){
+        for(k=0; k<s.iErr && s.zJson[k]; k++){
           if( (s.zJson[k] & 0xc0)!=0x80 ) iErrPos++;
         }
         iErrPos++;