Fix T55503: File browser filter not working correctly.

There were two issues here, introduced by rB66aa4af836:
* Forgot to change length of some filter_glob var deep in filebrowser code.
* Truncating filter_glob in general can be dangerous, generating
unexpected patterns.

Last point was the root of the issue here, truncating to 63 chars string
left last group as 'match everything' `*` pattern.

To fix that to some extent, added a new BLI_path_extension_glob_validate
helper to BLI_path_util, which ensures we do not have last
wildcards-only group in our pattern, when there are more than one group.

source/blender/blenlib/BLI_path_util.h

@@ -75,6 +75,7 @@ bool BLI_path_extension_check(const char *str, const char *ext) ATTR_NONNULL() A
 bool BLI_path_extension_check_n(const char *str, ...) ATTR_NONNULL(1) ATTR_SENTINEL(0);
 bool BLI_path_extension_check_array(const char *str, const char **ext_array) ATTR_NONNULL() ATTR_WARN_UNUSED_RESULT;
 bool BLI_path_extension_check_glob(const char *str, const char *ext_fnmatch) ATTR_NONNULL() ATTR_WARN_UNUSED_RESULT;
+bool BLI_path_extension_glob_validate(char *ext_fnmatch) ATTR_NONNULL();
 bool BLI_path_extension_replace(char *path, size_t maxlen, const char *ext) ATTR_NONNULL();
 bool BLI_path_extension_ensure(char *path, size_t maxlen, const char *ext) ATTR_NONNULL();
 bool BLI_ensure_filename(char *filepath, size_t maxlen, const char *filename) ATTR_NONNULL();

source/blender/blenlib/intern/path_util.c

@@ -1438,6 +1438,37 @@ bool BLI_path_extension_check_glob(const char *str, const char *ext_fnmatch)
 	return false;
 }
 
+/**
+ * Does basic validation of the given glob string, to prevent common issues from string truncation.
+ *
+ * For now, only forbids last group to be a wildcard-only one, if there are more than one group
+ * (i.e. things like "*.txt;*.cpp;*" are changed to "*.txt;*.cpp;")
+ *
+ * \returns true if it had to modify given \a ext_fnmatch pattern.
+ */
+bool BLI_path_extension_glob_validate(char *ext_fnmatch)
+{
+	bool only_wildcards = false;
+
+	for (size_t i = strlen(ext_fnmatch); i-- > 0; ) {
+		if (ext_fnmatch[i] == ';') {
+			/* Group separator, we truncate here if we only had wildcards so far. Otherwise, all is sound and fine. */
+			if (only_wildcards) {
+				ext_fnmatch[i] = '\0';
+				return true;
+			}
+			return false;
+		}
+		if (!ELEM(ext_fnmatch[i], '?', '*')) {
+			/* Non-wildcard char, we can break here and consider the pattern valid. */
+			return false;
+		}
+		/* So far, only wildcards in last group of the pattern... */
+		only_wildcards = true;
+	}
+	/* Only one group in the pattern, so even if its only made of wildcard(s), it is assumed vaid. */
+	return false;
+}
 
 /**
  * Removes any existing extension on the end of \a path and appends \a ext.

source/blender/editors/space_file/filelist.c

@@ -267,10 +267,11 @@ typedef struct FileListEntryPreview {
 	ImBuf *img;
 } FileListEntryPreview;
 
+
 typedef struct FileListFilter {
 	unsigned int filter;
 	unsigned int filter_id;
-	char filter_glob[256];
+	char filter_glob[FILE_MAXFILE];
 	char filter_search[66];  /* + 2 for heading/trailing implicit '*' wildcards. */
 	short flags;
 } FileListFilter;
@@ -2464,7 +2465,7 @@ static void filelist_readjob_do(
 	BLI_Stack *todo_dirs;
 	TodoDir *td_dir;
 	char dir[FILE_MAX_LIBEXTRA];
-	char filter_glob[64];  /* TODO should be define! */
+	char filter_glob[FILE_MAXFILE];
 	const char *root = filelist->filelist.root;
 	const int max_recursion = filelist->max_recursion;
 	int nbr_done_dirs = 0, nbr_todo_dirs = 1;

source/blender/editors/space_file/filesel.c

@@ -196,6 +196,10 @@ short ED_fileselect_set_params(SpaceFile *sfile)
 			if (tmp != params->filter_glob) {
 				BLI_strncpy(params->filter_glob, tmp, sizeof(params->filter_glob));
 				MEM_freeN(tmp);
+
+				/* Fix stupid things that truncating might have generated,
+				 * like last group being a 'match everything' wildcard-only one... */
+				BLI_path_extension_glob_validate(params->filter_glob);
 			}
 			params->filter |= (FILE_TYPE_OPERATOR | FILE_TYPE_FOLDER);
 		}

source/blender/makesdna/DNA_space_types.h

@@ -630,7 +630,7 @@ typedef struct FileSelectParams {
 	char renamefile[256];
 	char renameedit[256]; /* annoying but the first is only used for initialization */
 
-	char filter_glob[256]; /* list of filetypes to filter */
+	char filter_glob[256]; /* FILE_MAXFILE */ /* list of filetypes to filter */
 
 	char filter_search[64];  /* text items' name must match to be shown. */
 	int filter_id;  /* same as filter, but for ID types (aka library groups). */

source/blender/makesrna/intern/rna_space.c

@@ -258,6 +258,8 @@ const EnumPropertyItem rna_enum_file_sort_items[] = {
 #include "DNA_userdef_types.h"
 
 #include "BLI_math.h"
+#include "BLI_path_util.h"
+#include "BLI_string.h"
 
 #include "BKE_animsys.h"
 #include "BKE_brush.h"
@@ -1634,6 +1636,16 @@ static const EnumPropertyItem *rna_FileSelectParams_recursion_level_itemf(
 	return fileselectparams_recursion_level_items;
 }
 
+static void rna_FileSelectPrams_filter_glob_set(PointerRNA *ptr, const char *value)
+{
+	FileSelectParams *params = ptr->data;
+
+	BLI_strncpy(params->filter_glob, value, sizeof(params->filter_glob));
+
+	/* Remove stupi things like last group being a wildcard-only one... */
+	BLI_path_extension_glob_validate(params->filter_glob);
+}
+
 static void rna_FileBrowser_FSMenuEntry_path_get(PointerRNA *ptr, char *value)
 {
 	char *path = ED_fsmenu_entry_get_path(ptr->data);
@@ -4038,7 +4050,10 @@ static void rna_def_fileselect_params(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "filter_glob", PROP_STRING, PROP_NONE);
 	RNA_def_property_string_sdna(prop, NULL, "filter_glob");
-	RNA_def_property_ui_text(prop, "Extension Filter", "");
+	RNA_def_property_ui_text(prop, "Extension Filter",
+	                         "UNIX shell-like filename patterns matching, supports wildcards ('*') "
+	                         "and list of patterns separated by ';'");
+	RNA_def_property_string_funcs(prop, NULL, NULL, "rna_FileSelectPrams_filter_glob_set");
 	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_FILE_LIST, NULL);
 
 	prop = RNA_def_property(srna, "filter_search", PROP_STRING, PROP_NONE);