Add OpenStep coercion support for non-OpenStep plist typesHEADmaster

- Use PLIST_OPT_COERCE option to coerce PLIST_BOOLEAN, PLIST_DATE, PLIST_UID, and PLIST_NULL to OpenStep-compatible types (1 or 0, ISO 8601 strings, integers, and 'NULL' string)
- Add plist_to_openstep_with_options() function to allow passing coercion option (and others)
- Update plist_write_to_string() and plist_write_to_stream() accordingly

5 files changed, 164 insertions, 35 deletions

diff --git a/docs/plistutil.1 b/docs/plistutil.1
index f322bab..64373b3 100644
--- a/docs/plistutil.1
+++ b/docs/plistutil.1
@@ -79,6 +79,17 @@ A nodepath of:
 JSON and OpenStep only: Print output in compact form. By default, the output
 will be pretty-printed.
 .TP
+.B \-C, \-\-coerce
+JSON and OpenStep only: Coerce non-compatible plist types to JSON/OpenStep
+compatible representations.
+Date values become ISO 8601 strings,
+data values become Base64-encoded strings (JSON),
+UID values become integers,
+boolean becomes 1 or 0 (OpenStep),
+and NULL becomes a string 'NULL' (OpenStep)
+
+This options is implied when invoked as plist2json.
+.TP
 .B \-s, \-\-sort
 Sort all dictionary nodes lexicographically by key before converting to the output format.
 .TP
diff --git a/include/plist/plist.h b/include/plist/plist.h
index bd35c53..94930b8 100644
--- a/include/plist/plist.h
+++ b/include/plist/plist.h
@@ -978,6 +978,30 @@ extern "C"
      */
     PLIST_API plist_err_t plist_to_openstep(plist_t plist, char **plist_openstep, uint32_t* length, int prettify);
 
+    /**
+     * Export the #plist_t structure to OpenStep format with extended options.
+     *
+     * When \a PLIST_OPT_COMPACT is set in \a options, the resulting OpenStep output
+     * will be non-prettified.
+     *
+     * When \a PLIST_OPT_COERCE is set in \a options, plist types that have
+     * no native OpenStep representation are converted to OpenStep-compatible types
+     * instead of returning #PLIST_ERR_FORMAT:
+     * - #PLIST_BOOLEAN is serialized as a 1 or 0
+     * - #PLIST_DATE is serialized as an ISO 8601 date string
+     * - #PLIST_NULL is serialized as string 'NULL'
+     * - #PLIST_UID is serialized as an integer
+     *
+     * @param plist the root node to export
+     * @param plist_openstep a pointer to a char* buffer. This function allocates the memory,
+     *     caller is responsible for freeing it.
+     * @param length a pointer to an uint32_t variable. Represents the length of the allocated buffer.
+     * @param options One or more bitwise ORed values of #plist_write_options_t.
+     * @return PLIST_ERR_SUCCESS on success or a #plist_err_t on failure
+     * @note Use plist_mem_free() to free the allocated memory.
+     */
+    PLIST_API plist_err_t plist_to_openstep_with_options(plist_t plist, char **plist_openstep, uint32_t* length, plist_write_options_t options);
+
 
     /**
      * Import the #plist_t structure from XML format.
diff --git a/src/oplist.c b/src/oplist.c
index 0eea27a..3c48b3a 100644
--- a/src/oplist.c
+++ b/src/oplist.c
@@ -37,8 +37,11 @@
 
 #include "plist.h"
 #include "strbuf.h"
+#include "time64.h"
 #include "hashtable.h"
 
+#define MAC_EPOCH 978307200
+
 #ifdef DEBUG
 static int plist_ostep_debug = 0;
 #define PLIST_OSTEP_ERR(...) if (plist_ostep_debug) { fprintf(stderr, "libplist[ostepparser] ERROR: " __VA_ARGS__); }
@@ -144,7 +147,7 @@ static int str_needs_quotes(const char* str, size_t len)
     return 0;
 }
 
-static plist_err_t node_to_openstep(node_t node, bytearray_t **outbuf, uint32_t depth, int prettify)
+static plist_err_t node_to_openstep(node_t node, bytearray_t **outbuf, uint32_t depth, int prettify, int coerce)
 {
     plist_data_t node_data = NULL;
 
@@ -235,7 +238,7 @@ static plist_err_t node_to_openstep(node_t node, bytearray_t **outbuf, uint32_t
                     str_buf_append(*outbuf, "  ", 2);
                 }
             }
-            plist_err_t res = node_to_openstep(ch, outbuf, depth+1, prettify);
+            plist_err_t res = node_to_openstep(ch, outbuf, depth+1, prettify, coerce);
             if (res < 0) {
                 return res;
             }
@@ -263,7 +266,7 @@ static plist_err_t node_to_openstep(node_t node, bytearray_t **outbuf, uint32_t
                     str_buf_append(*outbuf, "  ", 2);
                 }
             }
-            plist_err_t res = node_to_openstep(ch, outbuf, depth+1, prettify);
+            plist_err_t res = node_to_openstep(ch, outbuf, depth+1, prettify, coerce);
             if (res < 0) {
                 return res;
             }
@@ -302,19 +305,65 @@ static plist_err_t node_to_openstep(node_t node, bytearray_t **outbuf, uint32_t
         str_buf_append(*outbuf, ">", 1);
         } break;
     case PLIST_BOOLEAN:
-        PLIST_OSTEP_WRITE_ERR("PLIST_BOOLEAN type is not valid for OpenStep format\n");
-        return PLIST_ERR_FORMAT;
+        if (coerce) {
+            if (node_data->boolval) {
+                str_buf_append(*outbuf, "1", 1);
+            } else {
+                str_buf_append(*outbuf, "0", 1);
+            }
+        } else {
+            PLIST_OSTEP_WRITE_ERR("PLIST_BOOLEAN type is not valid for OpenStep format\n");
+            return PLIST_ERR_FORMAT;
+        }
+        break;
     case PLIST_NULL:
-        PLIST_OSTEP_WRITE_ERR("PLIST_NULL type is not valid for OpenStep format\n");
-        return PLIST_ERR_FORMAT;
+        if (coerce) {
+            str_buf_append(*outbuf, "NULL", 4);
+        } else {
+            PLIST_OSTEP_WRITE_ERR("PLIST_NULL type is not valid for OpenStep format\n");
+            return PLIST_ERR_FORMAT;
+        }
+        break;
     case PLIST_DATE:
-        // NOT VALID FOR OPENSTEP
-        PLIST_OSTEP_WRITE_ERR("PLIST_DATE type is not valid for OpenStep format\n");
-        return PLIST_ERR_FORMAT;
+        if (coerce) {
+            Time64_T timev = (Time64_T)node_data->realval + MAC_EPOCH;
+            struct TM _btime;
+            struct TM *btime = gmtime64_r(&timev, &_btime);
+            char datebuf[32];
+            size_t datelen = 0;
+            if (btime) {
+                struct tm _tmcopy;
+                copy_TM64_to_tm(btime, &_tmcopy);
+                datelen = strftime(datebuf, sizeof(datebuf), "%Y-%m-%dT%H:%M:%SZ", &_tmcopy);
+            }
+            if (datelen <= 0) {
+                datelen = snprintf(datebuf, sizeof(datebuf), "1970-01-01T00:00:00Z");
+            }
+            str_buf_append(*outbuf, "\"", 1);
+            str_buf_append(*outbuf, datebuf, datelen);
+            str_buf_append(*outbuf, "\"", 1);
+        } else {
+            // NOT VALID FOR OPENSTEP
+            PLIST_OSTEP_WRITE_ERR("PLIST_DATE type is not valid for OpenStep format\n");
+            return PLIST_ERR_FORMAT;
+        }
+        break;
     case PLIST_UID:
-        // NOT VALID FOR OPENSTEP
-        PLIST_OSTEP_WRITE_ERR("PLIST_UID type is not valid for OpenStep format\n");
-        return PLIST_ERR_FORMAT;
+        if (coerce) {
+            val = (char*)malloc(64);
+            if (node_data->length == 16) {
+                val_len = snprintf(val, 64, "%" PRIu64, node_data->intval);
+            } else {
+                val_len = snprintf(val, 64, "%" PRIi64, node_data->intval);
+            }
+            str_buf_append(*outbuf, val, val_len);
+            free(val);
+        } else {
+            // NOT VALID FOR OPENSTEP
+            PLIST_OSTEP_WRITE_ERR("PLIST_UID type is not valid for OpenStep format\n");
+            return PLIST_ERR_FORMAT;
+        }
+        break;
     default:
         return PLIST_ERR_UNKNOWN;
     }
@@ -360,7 +409,7 @@ static int num_digits_u(uint64_t i)
     return n;
 }
 
-static plist_err_t _node_estimate_size(node_t node, uint64_t *size, uint32_t depth, int prettify, hashtable_t *visited)
+static plist_err_t _node_estimate_size(node_t node, uint64_t *size, uint32_t depth, int prettify, int coerce, hashtable_t *visited)
 {
     plist_data_t data;
     if (!node) {
@@ -385,7 +434,7 @@ static plist_err_t _node_estimate_size(node_t node, uint64_t *size, uint32_t dep
         node_t ch;
         unsigned int n_children = node_n_children(node);
         for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {
-            plist_err_t res = _node_estimate_size(ch, size, depth + 1, prettify, visited);
+            plist_err_t res = _node_estimate_size(ch, size, depth + 1, prettify, coerce, visited);
             if (res < 0) {
                 return res;
             }
@@ -442,17 +491,46 @@ static plist_err_t _node_estimate_size(node_t node, uint64_t *size, uint32_t dep
                 *size += data->length/4;
             break;
         case PLIST_BOOLEAN:
-            // NOT VALID FOR OPENSTEP
-            PLIST_OSTEP_WRITE_ERR("PLIST_BOOLEAN type is not valid for OpenStep format\n");
-            return PLIST_ERR_FORMAT;
+            if (coerce) {
+                *size += 1;
+            } else {
+                // NOT VALID FOR OPENSTEP
+                PLIST_OSTEP_WRITE_ERR("PLIST_BOOLEAN type is not valid for OpenStep format\n");
+                return PLIST_ERR_FORMAT;
+            }
+            break;
         case PLIST_DATE:
-            // NOT VALID FOR OPENSTEP
-            PLIST_OSTEP_WRITE_ERR("PLIST_DATE type is not valid for OpenStep format\n");
-            return PLIST_ERR_FORMAT;
+            if (coerce) {
+                // ISO 8601 string: "YYYY-MM-DDTHH:MM:SSZ" = 22 chars max
+                *size += 24;
+            } else {
+                // NOT VALID FOR OPENSTEP
+                PLIST_OSTEP_WRITE_ERR("PLIST_DATE type is not valid for OpenStep format\n");
+                return PLIST_ERR_FORMAT;
+            }
+            break;
         case PLIST_UID:
-            // NOT VALID FOR OPENSTEP
-            PLIST_OSTEP_WRITE_ERR("PLIST_UID type is not valid for OpenStep format\n");
-            return PLIST_ERR_FORMAT;
+            if (coerce) {
+                if (data->length == 16) {
+                    *size += num_digits_u(data->intval);
+                } else {
+                    *size += num_digits_i((int64_t)data->intval);
+                }
+            } else {
+                // NOT VALID FOR OPENSTEP
+                PLIST_OSTEP_WRITE_ERR("PLIST_UID type is not valid for OpenStep format\n");
+                return PLIST_ERR_FORMAT;
+            }
+            break;
+        case PLIST_NULL:
+            if (coerce) {
+                *size += 4;
+            } else {
+                // NOT VALID FOR OPENSTEP
+                PLIST_OSTEP_WRITE_ERR("PLIST_NULL type is not valid for OpenStep format\n");
+                return PLIST_ERR_FORMAT;
+            }
+            break;
         default:
             PLIST_OSTEP_WRITE_ERR("invalid node type encountered\n");
             return PLIST_ERR_UNKNOWN;
@@ -461,17 +539,23 @@ static plist_err_t _node_estimate_size(node_t node, uint64_t *size, uint32_t dep
     return PLIST_ERR_SUCCESS;
 }
 
-static plist_err_t node_estimate_size(node_t node, uint64_t *size, uint32_t depth, int prettify)
+static plist_err_t node_estimate_size(node_t node, uint64_t *size, uint32_t depth, int prettify, int coerce)
 {
     hashtable_t *visited = hash_table_new(plist_node_ptr_hash, plist_node_ptr_compare, NULL);
     if (!visited) return PLIST_ERR_NO_MEM;
-    plist_err_t err = _node_estimate_size(node, size, depth, prettify, visited);
+    plist_err_t err = _node_estimate_size(node, size, depth, prettify, coerce, visited);
     hash_table_destroy(visited);
     return err;
 }
 
 plist_err_t plist_to_openstep(plist_t plist, char **openstep, uint32_t* length, int prettify)
 {
+    plist_write_options_t opts = prettify ? PLIST_OPT_NONE : PLIST_OPT_COMPACT;
+    return plist_to_openstep_with_options(plist, openstep, length, opts);
+}
+
+plist_err_t plist_to_openstep_with_options(plist_t plist, char **openstep, uint32_t* length, plist_write_options_t options)
+{
     uint64_t size = 0;
     plist_err_t res;
 
@@ -479,7 +563,10 @@ plist_err_t plist_to_openstep(plist_t plist, char **openstep, uint32_t* length,
         return PLIST_ERR_INVALID_ARG;
     }
 
-    res = node_estimate_size((node_t)plist, &size, 0, prettify);
+    int prettify = !(options & PLIST_OPT_COMPACT);
+    int coerce = options & PLIST_OPT_COERCE;
+
+    res = node_estimate_size((node_t)plist, &size, 0, prettify, coerce);
     if (res < 0) {
         return res;
     }
@@ -490,7 +577,7 @@ plist_err_t plist_to_openstep(plist_t plist, char **openstep, uint32_t* length,
         return PLIST_ERR_NO_MEM;
     }
 
-    res = node_to_openstep((node_t)plist, &outbuf, 0, prettify);
+    res = node_to_openstep((node_t)plist, &outbuf, 0, prettify, coerce);
     if (res < 0) {
         str_buf_free(outbuf);
         *openstep = NULL;
diff --git a/src/plist.c b/src/plist.c
index a6d3547..2ad1b0a 100644
--- a/src/plist.c
+++ b/src/plist.c
@@ -2407,7 +2407,7 @@ plist_err_t plist_write_to_string(plist_t plist, char **output, uint32_t* length
             err = plist_to_json_with_options(plist, output, length, options);
             break;
         case PLIST_FORMAT_OSTEP:
-            err = plist_to_openstep(plist, output, length, ((options & PLIST_OPT_COMPACT) == 0));
+            err = plist_to_openstep_with_options(plist, output, length, options);
             break;
         case PLIST_FORMAT_PRINT:
             err = plist_write_to_string_default(plist, output, length, options);
@@ -2445,7 +2445,7 @@ plist_err_t plist_write_to_stream(plist_t plist, FILE *stream, plist_format_t fo
             err = plist_to_json_with_options(plist, &output, &length, options);
             break;
         case PLIST_FORMAT_OSTEP:
-            err = plist_to_openstep(plist, &output, &length, ((options & PLIST_OPT_COMPACT) == 0));
+            err = plist_to_openstep_with_options(plist, &output, &length, options);
             break;
         case PLIST_FORMAT_PRINT:
             err = plist_write_to_stream_default(plist, stream, options);
diff --git a/tools/plistutil.c b/tools/plistutil.c
index fef72b7..95ec254 100644
--- a/tools/plistutil.c
+++ b/tools/plistutil.c
@@ -75,10 +75,14 @@ static void print_usage(int argc, char *argv[])
     printf("  -n, --nodepath PATH  Restrict output to nodepath defined by PATH.\n");
     printf("  -c, --compact        JSON and OpenStep only: Print output in compact form.\n");
     printf("                       By default, the output will be pretty-printed.\n");
-    printf("  -C, --coerce         JSON only: Coerce non-JSON plist types to JSON-compatible\n");
-    printf("                       representations. Date values become ISO 8601 strings,\n");
-    printf("                       data values become Base64-encoded strings, and UID values\n");
-    printf("                       become integers. Implied when invoked as plist2json.\n");
+    printf("  -C, --coerce         JSON + OpenStep only: Coerce non-compatible plist types\n");
+    printf("                       to JSON/OpenStep compatible representations.\n");
+    printf("                       Date values become ISO 8601 strings,\n");
+    printf("                       data values become Base64-encoded strings (JSON),\n");
+    printf("                       UID values become integers,\n");
+    printf("                       boolean becomes 1 or 0 (OpenStep),\n");
+    printf("                       and NULL becomes a string 'NULL' (OpenStep)\n");
+    printf("                       This options is implied when invoked as plist2json.\n");
     printf("  -s, --sort           Sort all dictionary nodes lexicographically by key\n");
     printf("                       before converting to the output format.\n");
     printf("  -d, --debug          Enable extended debug output\n");
@@ -431,7 +435,10 @@ int main(int argc, char *argv[])
                 if (options->flags & OPT_COERCE) wropts |= PLIST_OPT_COERCE;
                 output_res = plist_to_json_with_options(root_node, &plist_out, &size, wropts);
             } else if (options->out_fmt == PLIST_FORMAT_OSTEP) {
-                output_res = plist_to_openstep(root_node, &plist_out, &size, !(options->flags & OPT_COMPACT));
+                plist_write_options_t wropts = PLIST_OPT_NONE;
+                if (options->flags & OPT_COMPACT) wropts |= PLIST_OPT_COMPACT;
+                if (options->flags & OPT_COERCE) wropts |= PLIST_OPT_COERCE;
+                output_res = plist_to_openstep_with_options(root_node, &plist_out, &size, wropts);
             } else {
                 plist_write_to_stream(root_node, stdout, options->out_fmt, PLIST_OPT_PARTIAL_DATA);
                 plist_free(root_node);