Text: use simplified logic for txt_to_buf

This function was copied from txt_sel_to_buf, including unnecessary
complexity to support selection as well as checks for the cursor
which don't make sense when copying the whole buffer.

Use a simple loop to copy all text into the destination buffer.

source/blender/blenkernel/BKE_text.h

@@ -14,6 +14,8 @@ struct Main;
 struct Text;
 struct TextLine;
 
+#include "BLI_compiler_attrs.h"
+
 /**
  * \note caller must handle `compiled` member.
  */
@@ -55,7 +57,8 @@ void BKE_text_write(struct Text *text, const char *str);
 int BKE_text_file_modified_check(struct Text *text);
 void BKE_text_file_modified_ignore(struct Text *text);
 
-char *txt_to_buf(struct Text *text, int *r_buf_strlen);
+char *txt_to_buf(struct Text *text, int *r_buf_strlen)
+    ATTR_NONNULL(1, 2) ATTR_WARN_UNUSED_RESULT ATTR_RETURNS_NONNULL;
 void txt_clean_text(struct Text *text);
 void txt_order_cursors(struct Text *text, bool reverse);
 int txt_find_string(struct Text *text, const char *findstr, int wrap, int match_case);
@@ -135,11 +138,12 @@ enum {
 /**
  * Create a buffer, the only requirement is #txt_from_buf_for_undo can decode it.
  */
-char *txt_to_buf_for_undo(struct Text *text, int *r_buf_len);
+char *txt_to_buf_for_undo(struct Text *text, int *r_buf_len)
+    ATTR_NONNULL(1, 2) ATTR_WARN_UNUSED_RESULT ATTR_RETURNS_NONNULL;
 /**
  * Decode a buffer from #txt_to_buf_for_undo.
  */
-void txt_from_buf_for_undo(struct Text *text, const char *buf, int buf_len);
+void txt_from_buf_for_undo(struct Text *text, const char *buf, int buf_len) ATTR_NONNULL(1, 2);
 
 #ifdef __cplusplus
 }

source/blender/blenkernel/intern/text.c

@@ -1436,78 +1436,20 @@ void txt_from_buf_for_undo(Text *text, const char *buf, int buf_len)
 
 char *txt_to_buf(Text *text, int *r_buf_strlen)
 {
-  int length;
-  TextLine *tmp, *linef, *linel;
-  int charf, charl;
-  char *buf;
-
-  if (r_buf_strlen) {
-    *r_buf_strlen = 0;
+  /* Identical to #txt_to_buf_for_undo except that the string is nil terminated. */
+  int buf_len = 0;
+  LISTBASE_FOREACH (const TextLine *, l, &text->lines) {
+    buf_len += l->len + 1;
   }
-
-  if (!text->curl) {
-    return NULL;
+  char *buf = MEM_mallocN(buf_len + 1, __func__);
+  char *buf_step = buf;
+  LISTBASE_FOREACH (const TextLine *, l, &text->lines) {
+    memcpy(buf_step, l->line, l->len);
+    buf_step += l->len;
+    *buf_step++ = '\n';
   }
-  if (!text->sell) {
-    return NULL;
-  }
-  if (!text->lines.first) {
-    return NULL;
-  }
-
-  linef = text->lines.first;
-  charf = 0;
-
-  linel = text->lines.last;
-  charl = linel->len;
-
-  if (linef == text->lines.last) {
-    length = charl - charf;
-
-    buf = MEM_mallocN(length + 2, "text buffer");
-
-    BLI_strncpy(buf, linef->line + charf, length + 1);
-    buf[length] = 0;
-  }
-  else {
-    length = linef->len - charf;
-    length += charl;
-    length += 2; /* For the 2 '\n' */
-
-    tmp = linef->next;
-    while (tmp && tmp != linel) {
-      length += tmp->len + 1;
-      tmp = tmp->next;
-    }
-
-    buf = MEM_mallocN(length + 1, "cut buffer");
-
-    strncpy(buf, linef->line + charf, linef->len - charf);
-    length = linef->len - charf;
-
-    buf[length++] = '\n';
-
-    tmp = linef->next;
-    while (tmp && tmp != linel) {
-      strncpy(buf + length, tmp->line, tmp->len);
-      length += tmp->len;
-
-      buf[length++] = '\n';
-
-      tmp = tmp->next;
-    }
-    strncpy(buf + length, linel->line, charl);
-    length += charl;
-
-    /* python compiler wants an empty end line */
-    buf[length++] = '\n';
-    buf[length] = 0;
-  }
-
-  if (r_buf_strlen) {
-    *r_buf_strlen = length;
-  }
-
+  *buf_step = '\0';
+  *r_buf_strlen = buf_len;
   return buf;
 }
 

source/blender/python/intern/bpy_interface_run.c

@@ -102,7 +102,8 @@ static bool python_script_exec(
 
       fn_dummy_py = PyC_UnicodeFromByte(fn_dummy);
 
-      buf = txt_to_buf(text, NULL);
+      int buf_len_dummy;
+      buf = txt_to_buf(text, &buf_len_dummy);
       text->compiled = Py_CompileStringObject(buf, fn_dummy_py, Py_file_input, NULL, -1);
       MEM_freeN(buf);