From 3a7ae150b8fac1c108c28aa934b4650b7ad76577 Mon Sep 17 00:00:00 2001
From: Rongsong Shen <rongsong.shen@akrostar-tech.com>
Date: Sun, 27 Apr 2025 17:52:42 +0800
Subject: [PATCH] handle NULL text

---
 compiler/capnpc-c.c      | 23 +++++++++++++++++------
 examples/book/book.capnp |  1 +
 examples/book/book.h     |  1 +
 examples/book/test.c     |  1 +
 4 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/compiler/capnpc-c.c b/compiler/capnpc-c.c
index 67dcf5f..8d98544 100644
--- a/compiler/capnpc-c.c
+++ b/compiler/capnpc-c.c
@@ -1070,9 +1070,21 @@ static void encode_member(capnp_ctx_t *ctx, struct str *func, struct field *f,
     break;
   case Type_text:
     str_add(func, tab, -1);
-    str_addf(func, "d->%s.str = s->%s;\n", var, var2);
+    str_addf(func, "if (s->%s != NULL) {\n", var2);
     str_add(func, tab, -1);
-    str_addf(func, "d->%s.len = strlen(s->%s);\n", var, var2);
+    str_addf(func, "\td->%s.str = s->%s;\n", var, var2);
+    str_add(func, tab, -1);
+    str_addf(func, "\td->%s.len = strlen(s->%s);\n", var, var2);
+    str_add(func, tab, -1);
+    str_addf(func, "}\n");
+    str_add(func, tab, -1);
+    str_addf(func, "else{\n");
+    str_add(func, tab, -1);
+    str_addf(func, "\td->%s.str = \"\";\n", var);
+    str_add(func, tab, -1);
+    str_addf(func, "\td->%s.len = 0;\n", var);
+    str_add(func, tab, -1);
+    str_addf(func, "}\n");
     str_add(func, tab, -1);
     str_addf(func, "d->%s.seg = NULL;\n", var);
     break;
@@ -1081,8 +1093,8 @@ static void encode_member(capnp_ctx_t *ctx, struct str *func, struct field *f,
 
     if (n != NULL) {
       str_add(func, tab, -1);
-      str_addf(func, "encode_%s_ptr(cs, &(d->%s), s->%s);\n", n->name.str,
-               var, var2);
+      str_addf(func, "encode_%s_ptr(cs, &(d->%s), s->%s);\n", n->name.str, var,
+               var2);
     }
     break;
   case Type__list:
@@ -1323,8 +1335,7 @@ void mk_struct_ptr_decoder(capnp_ctx_t *ctx, struct node *n) {
            "%s_ptr p) {\n",
            n->name.str, buf, n->name.str);
   str_addf(&(ctx->SRC), "\tstruct %s s;\n", n->name.str);
-  str_addf(&(ctx->SRC), "\t*d = (%s *)calloc(1, sizeof(%s));\n",
-	   buf, buf);
+  str_addf(&(ctx->SRC), "\t*d = (%s *)calloc(1, sizeof(%s));\n", buf, buf);
   str_addf(&(ctx->SRC), "\tread_%s(&s, p);\n", n->name.str);
   str_addf(&(ctx->SRC), "\tdecode_%s(*d, &s);\n", n->name.str);
   str_addf(&(ctx->SRC), "}\n");
diff --git a/examples/book/book.capnp b/examples/book/book.capnp
index 7035124..c9c13ac 100644
--- a/examples/book/book.capnp
+++ b/examples/book/book.capnp
@@ -27,6 +27,7 @@ struct Book $C.mapname("book_t") {
   publish  @6: Publish;
   nulldata @7: Nulldata;
   magic1  @2: List(UInt32) $C.mapname("magic_1") $C.maplistcount("n_magic1");
+  description @8: Text;
   acquire :union $C.mapuniontag("acquire_method") {
     buy   @3: Text;
     donation @4: Text;
diff --git a/examples/book/book.h b/examples/book/book.h
index fb11afd..2c6bd77 100644
--- a/examples/book/book.h
+++ b/examples/book/book.h
@@ -30,6 +30,7 @@ typedef struct {
     nulldata_t *nulldata;
     int   n_magic1;
     uint32_t *magic_1;
+    char *description;
     int   acquire_method;
     union {
 	char *buy;
diff --git a/examples/book/test.c b/examples/book/test.c
index 34334fa..357f918 100644
--- a/examples/book/test.c
+++ b/examples/book/test.c
@@ -48,6 +48,7 @@ int encode() {
     book.nulldata = NULL;
     book.n_magic1 = 2;
     book.magic_1 = &magic1[0];
+    book.description = NULL;
     book.acquire_method = Book_acquire_buy;
     book.acquire.buy = "bought from Xinhua book store";