Harden checks in datatoc_icon binary

The goal of the change is to perform check for attempts of icons
being overwritten on canvas. The check is based on checking original
coordinate of icons against all read icons. If there are two icon
files which have same original an error will be reported. The report
includes both file names to make it easier to troubleshoot.

This change will allow to early-on catch issues which we currently
have with the release environment: official Linux builds might have
different icon from Blender compiled locally. This is because the
order in which directory listing is traversed is not defined, so
it's like a race condition between two files to win the place in
the final canvas.

There is still possible improvement in the code to move more fields
into the context structure. This is beyond of goal of this change.

Note that before committing this change icons must be brought back
to their consistent state. Otherwise the build will fail.

Differential Revision: https://developer.blender.org/D9715

1 files changed, 105 insertions, 3 deletions

diff --git a/source/blender/datatoc/datatoc_icon.c b/source/blender/datatoc/datatoc_icon.c
index 4a9c5875c17..f4f510891e0 100644
--- a/source/blender/datatoc/datatoc_icon.c
+++ b/source/blender/datatoc/datatoc_icon.c
@@ -72,6 +72,27 @@ static void endian_switch_uint32(unsigned int *val)
   *val = ((tval >> 24)) | ((tval << 8) & 0x00ff0000) | ((tval >> 8) & 0x0000ff00) | ((tval << 24));
 }
 
+static const char *path_slash_rfind(const char *string)
+{
+  const char *const lfslash = strrchr(string, '/');
+  const char *const lbslash = strrchr(string, '\\');
+
+  if (!lfslash) {
+    return lbslash;
+  }
+  if (!lbslash) {
+    return lfslash;
+  }
+
+  return (lfslash > lbslash) ? lfslash : lbslash;
+}
+
+static const char *path_basename(const char *path)
+{
+  const char *const filename = path_slash_rfind(path);
+  return filename ? filename + 1 : path;
+}
+
 /* -------------------------------------------------------------------- */
 /* Write a PNG from RGBA pixels */
 
@@ -183,6 +204,71 @@ struct IconHead {
   unsigned int canvas_w, canvas_h;
 };
 
+struct IconInfo {
+  struct IconHead head;
+  char *file_name;
+};
+
+struct IconMergeContext {
+  /* Information about all icons read from disk.
+   * Is used for sanity checks like prevention of two files defining icon for
+   * the same position on canvas. */
+  int num_read_icons;
+  struct IconInfo *read_icons;
+};
+
+static void icon_merge_context_init(struct IconMergeContext *context)
+{
+  context->num_read_icons = 0;
+  context->read_icons = NULL;
+}
+
+/* Get icon information from the context which matches given icon head.
+ * Is used to check whether icon is re-defined, and to provide useful information about which
+ * files are conflicting. */
+static struct IconInfo *icon_merge_context_info_for_icon_head(struct IconMergeContext *context,
+                                                              struct IconHead *icon_head)
+{
+  if (context->read_icons == NULL) {
+    return NULL;
+  }
+
+  for (int i = 0; i < context->num_read_icons; i++) {
+    struct IconInfo *read_icon_info = &context->read_icons[i];
+    const struct IconHead *read_icon_head = &read_icon_info->head;
+    if (read_icon_head->orig_x == icon_head->orig_x &&
+        read_icon_head->orig_y == icon_head->orig_y) {
+      return read_icon_info;
+    }
+  }
+
+  return NULL;
+}
+
+static void icon_merge_context_register_icon(struct IconMergeContext *context,
+                                             const char *file_name,
+                                             struct IconHead *icon_head)
+{
+  context->read_icons = realloc(context->read_icons,
+                                sizeof(struct IconInfo) * (context->num_read_icons + 1));
+
+  struct IconInfo *icon_info = &context->read_icons[context->num_read_icons];
+  icon_info->head = *icon_head;
+  icon_info->file_name = strdup(path_basename(file_name));
+
+  context->num_read_icons++;
+}
+
+static void icon_merge_context_free(struct IconMergeContext *context)
+{
+  if (context->read_icons != NULL) {
+    for (int i = 0; i < context->num_read_icons; i++) {
+      free(context->read_icons[i].file_name);
+    }
+    free(context->read_icons);
+  }
+}
+
 static bool icon_decode_head(FILE *f_src, struct IconHead *r_head)
 {
   if (fread(r_head, 1, sizeof(*r_head), f_src) == sizeof(*r_head)) {
@@ -247,7 +333,8 @@ static bool icon_read(const char *file_src, struct IconHead *r_head, unsigned in
   return success;
 }
 
-static bool icon_merge(const char *file_src,
+static bool icon_merge(struct IconMergeContext *context,
+                       const char *file_src,
                        unsigned int **r_pixels_canvas,
                        unsigned int *r_canvas_w,
                        unsigned int *r_canvas_h)
@@ -265,6 +352,15 @@ static bool icon_merge(const char *file_src,
     return false;
   }
 
+  struct IconInfo *read_icon_info = icon_merge_context_info_for_icon_head(context, &head);
+  if (read_icon_info != NULL) {
+    printf(
+        "Conflicting icon files %s and %s\n", path_basename(file_src), read_icon_info->file_name);
+    free(pixels);
+    return false;
+  }
+  icon_merge_context_register_icon(context, file_src, &head);
+
   if (*r_canvas_w == 0) {
     /* init once */
     *r_canvas_w = head.canvas_w;
@@ -315,9 +411,13 @@ static bool icondir_to_png(const char *path_src, const char *file_dst)
   int path_str_len;
   int found = 0, fail = 0;
 
+  struct IconMergeContext context;
+
   unsigned int *pixels_canvas = NULL;
   unsigned int canvas_w = 0, canvas_h = 0;
 
+  icon_merge_context_init(&context);
+
   errno = 0;
   dir = opendir(path_src);
   if (dir == NULL) {
@@ -335,7 +435,7 @@ static bool icondir_to_png(const char *path_src, const char *file_dst)
 
       strcpy(filename, fname->d_name);
 
-      if (icon_merge(filepath, &pixels_canvas, &canvas_w, &canvas_h)) {
+      if (icon_merge(&context, filepath, &pixels_canvas, &canvas_w, &canvas_h)) {
         found++;
       }
       else {
@@ -344,6 +444,8 @@ static bool icondir_to_png(const char *path_src, const char *file_dst)
     }
   }
 
+  icon_merge_context_free(&context);
+
   closedir(dir);
 
   if (found == 0) {
@@ -359,7 +461,7 @@ static bool icondir_to_png(const char *path_src, const char *file_dst)
 
   free(pixels_canvas);
 
-  return true;
+  return (fail == 0);
 }
 
 /* -------------------------------------------------------------------- */