Make dmenu reading very marginally faster

A slight reduction in use of realloc and avoidance of 3 or 4 strlens for
a string we know the length of

include/helper.h

@@ -16,7 +16,7 @@ int helper_parse_setup ( char * string, char ***output, int *length, ... );
 /**
  * Implementation of fgets with custom separator.
  */
-char* fgets_s ( char* s, int n, FILE *iop, char sep );
+char* fgets_s ( char* s, unsigned int n, FILE *iop, char sep );
 
 /**
  * @param token The string for which we want a collation key.

source/dialogs/dmenu.c

@@ -59,28 +59,40 @@ typedef struct _DmenuModePrivateData
 
 static char **get_dmenu ( unsigned int *length )
 {
-    char buffer[1024];
+    const unsigned int buf_size = 1024;
+    char buffer[buf_size];
     char **retv = NULL;
+    char *buffer_end = NULL;
+    unsigned int rvlength = 1;
 
     *length = 0;
 
-    while ( fgets_s ( buffer, 1024, stdin, (char) config.separator ) != NULL ) {
-        retv                  = g_realloc ( retv, ( ( *length ) + 2 ) * sizeof ( char* ) );
-        retv[( *length )]     = g_strdup ( buffer );
-        retv[( *length ) + 1] = NULL;
+    while ( ( buffer_end = fgets_s ( buffer, buf_size, stdin, (char) config.separator ) ) != NULL ) {
+        if (rvlength < (*length + 2)) {
+          rvlength *= 2;
+          retv      = g_realloc ( retv, ( rvlength ) * sizeof ( char* ) );
+        }
+
+        size_t blength = buffer_end - &(buffer[0]);
+
+        char *copy = g_malloc( blength + 1 );
+        memcpy(copy, buffer, blength);
 
         // Filter out line-end.
-        if ( retv[( *length )][strlen ( buffer ) - 1] == '\n' ) {
-            retv[( *length )][strlen ( buffer ) - 1] = '\0';
+        if ( copy[blength] == '\n' ) {
+            copy[blength] = '\0';
         }
 
+        retv[( *length )]     = copy;
+        retv[( *length ) + 1] = NULL;
+
         ( *length )++;
         // Stop when we hit 2³¹ entries.
         if ( ( *length ) == INT_MAX ) {
             return retv;
         }
     }
-
+    retv      = g_realloc ( retv, ( *length + 1 ) * sizeof ( char* ) );
     return retv;
 }
 

source/helper.c

@@ -52,7 +52,7 @@ void cmd_set_arguments ( int argc, char **argv )
 /**
  *  `fgets` implementation with custom separator.
  */
-char* fgets_s ( char* s, int n, FILE *iop, char sep )
+char* fgets_s ( char* s, unsigned int n, FILE *iop, char sep )
 {
     // Map these to registers.
     register int c = EOF;
@@ -72,7 +72,7 @@ char* fgets_s ( char* s, int n, FILE *iop, char sep )
     *cs = '\0';
     // if last read was end of file and current index is start, we are done:
     // Return NULL.
-    return ( c == EOF && cs == s ) ? NULL : s;
+    return ( c == EOF && cs == s ) ? NULL : cs;
 }
 
 /**